1. art and entertainment
2. visual art and design
3. design

Designing Fabric Interactions
A study of knitted fabrics as an electronic interface medium
Ramyah Gowrishankar
Master of Arts Thesis
Media Lab Helsinki
Department of Media
School of Art and Design
Aalto University, 2011
Author
Author
Title
Title
Ra
my
a
hGo
wr
i
s
ha
nka
r
Ramyah Gowrishankar
Department
Department
Me
di
aLa
bHe
l
s
i
nki
,De
pt
.o
fMe
di
a
,
Media Lab Helsinki, Dept. of Media,
Aa
l
t
oUni
v
e
r
s
i
t
y
Aalto University
Year of publication
Year of publication
2011
2011
Degree programme
Degree programme
MAi
nNe
wMe
di
a
MA in New Media
De
s
i
g
n
i
ngf
a
br
i
c
i
nt
e
r
a
c
t
i
o
ns–Ane
p
l
o
r
a
t
i
o
n
o
fkni
t
t
e
df
a
br
i
c
s
s
me
di
ume
l
e
c
t
r
o
ni
c
i
nt
e
r
f
a
c
e
s
Designing
fabric
interactions:
Ax
study
of
knitted
fabrics
as
ana
electronic
interface
medium
Type of Type
work of work
Ma
s
t
e
r
'
st
he
s
i
s
Master's
thesis
Language
Language
Eng
l
i
s
h
English
Number
of pages
Number
of pages
111
AbstractAbstract
Thefie
l
do
fe
l
e
c
t
r
o
ni
ct
e
x
t
i
l
e
s
t
ho
ug
h
ay
o
ungao
n
e
,ha
sone,
g
a
i
ne
dmgained
o
me
nt
u
mi
nt
hel
a
s
td
e
c
a
d
e
.C
r
e
a
t
i
v
eTextiles
The
field
of
electronic
textiles
although
young
has
momentum
in
the
last
decade.
pr
a
c
t
i
t
i
o
ne
r
swo
r
k
n
gi
nt
hefi
e
l
dof
o
f
e
t
e
x
t
i
l
e
sa
i
m
t
e
f
fic
i
e
nt
l
y
o
mbi
ni
nge
l
e
c
t
r
o
ni
c
swi
t
h
r
a
di
t
i
o
na
l needs
have
been
ani
integral
part
our
cultures
fora
thousands
ofc
years
and
have
adapted
tot
the
different
f
a
br
i
cand
ma
t
e
r
i
a
l
s
.
H
o
w
e
v
e
r
,
n
o
t
m
a
n
y
h
a
v
e
t
r
i
e
d
t
o
d
e
r
i
v
e
i
n
s
p
i
r
a
t
i
o
n
f
r
o
m
t
h
e
e
x
i
s
t
i
n
g
l
a
n
g
u
a
g
e
o
f
f
a
b
r
i
c
s
lives of people. They provide a rich source for interactions and scenarios from the context
of our
t
ode
s
i
g
nt
he
s
ei
nt
e
r
f
a
c
e
s
.
Mo
s
to
f
t
hec
o
mme
r
c
i
a
lelectronic
e
t
e
x
t
i
l
epr
o
duc
t
s
,t
ho
u
g
hi
nc
o
r
p
o
r
a
t
i
ngc
ut
t
i
n
g
e
dg
ein the
everyday
lives
that
can
be
reinterpreted
for
interfacing.
Creative
practitioners
working
t
e
c
hno
l
o
g
i
e
s
,s
e
e
mt
oc
o
pyo
rd
i
r
e
c
t
l
yf
o
l
l
o
wpr
e
v
i
o
us
t
r
e
ndsi
nw
e
a
r
a
bl
ec
o
mput
i
ngr
a
t
he
rt
ha
nt
r
ul
y
field
of
e-textiles
aim
at
efficiently
combining
electronics
with
traditional
fabric
materials.
However,
not
a
t
t
e
mp
t
i
ngt
ode
s
i
g
ns
p
c
i
fic
a
l
l
y
f
o
rt
heme
di
umthe
o
ff
a
br
i
c
s
.T
e
x
t
i
l
e
sha
e
be
e
na
i
nt
e
g
r
a
lpa
r
t
o
fo
ur Most
many
have
tried
toe
derive
inspiration
from
existing
language
ofv
fabrics
tondesign
these
interfaces.
c
ul
t
ur
e
o
rt
h
o
us
a
ndso
fy
e
a
r
sa
ndproducts,
ha
v
ea
da
p
t
e
dt
oincorporating
t
hedi
f
f
e
r
e
ntn
e
e
dsa
ndl
i
v
e
so
fpe
o
pl
e
.Th
e
ypr
o
i
d
ea or
ofsf
the
commercial
e-textile
while
cutting-edge
technologies,
seem
tov
copy
r
i
c
hs
o
u
r
c
e
f
o
r
i
n
t
e
r
a
c
t
i
o
n
s
a
n
d
s
c
e
n
a
r
i
o
s
f
r
o
m
t
h
e
c
o
n
t
e
x
t
o
f
o
u
r
e
v
e
r
y
d
a
y
l
i
v
e
s
t
h
a
t
c
a
n
b
e
r
e
i
n
t
e
r
p
r
e
t
e
d
directly follow previous trends in wearable computing rather than truly attempting to design specifically
f
o
re
l
e
c
t
r
o
ni
c
i
nt
e
r
f
a
c
i
ng
.
for
the
medium
of
fabrics.
Thet
h
e
s
i
se
x
pl
o
r
e
sme
t
ho
d
so
fi
nt
e
g
r
a
t
i
ngf
a
br
i
c
s
a
nde
l
e
c
t
r
o
ni
c
st
oc
r
e
a
e
i
nt
e
r
f
a
c
e
st
ha
ta
r
es
p
e
c
i
fi
ct
o to
This
thesis
explores
methods
of
integrating
fabrics
and
electronics
tot
create
interfaces
that
are
specific
t
heme
di
u
mo
ff
a
br
c
s
.Fo
l
l
o
w
i
ngt
hea
p
pr
o
a
c
ho
fl
udi
e
s
i
g
n
,t
hi
sw
o
r
ka
l
s
oe
mph
a
s
i
z
e
so
nt
he
po
t
e
nt
i
a
l of
the
medium
ofi
textiles.
Following
the
approach
ofcd
ludic
design,
this
work
also
emphasizes
the
potential
o
fe
t
e
x
t
i
l
ei
nt
e
r
f
a
c
e
st
oi
n
i
t
eune
x
pe
c
t
e
di
nt
e
r
pr
e
t
a
t
i
o
nsa
ndand
r
e
s
p
o
ns
e
sf
r
o
m
t
heu
s
e
r
s
whi
l
e
e
na
b
l
i
nga
n an
e-textile
interfaces
tov
invite
unexpected
interpretations
responses
from
the
users
while
enabling
a
c
t
i
v
e
,
c
r
e
a
t
i
v
er
e
l
a
t
i
o
ns
hi
pt
ot
he
i
rs
ur
r
o
und
i
ng
s
.Thepr
a
c
t
i
c
a
l
wo
r
kf
o
c
u
s
e
do
na
ni
nde
p
t
hin-depth
s
t
udyo
fstudy of
active,
creative
relationship
with
their
surroundings.
The
practical
work
focuses
on
an
knitted
fabrics
as
a medium
for
electronic
interfaces.
The
process
involves
working
and
experimenting
kni
t
t
e
d
f
a
br
i
c
s
a
sme
d
i
um
f
o
re
l
e
c
t
r
o
ni
c
i
nt
e
r
f
a
c
e
s
.Thepr
o
c
e
s
si
n
v
o
l
v
e
dw
o
r
ki
nga
nde
x
pe
r
i
me
n
t
i
ngwi
t
h
with
knitting
yarns,
conductive
threads
and
off-the-shelf
electronics
while
using
fabric
kni
t
t
i
n
gy
a
r
n
s
,c
o
ndu
c
t
i
v
et
h
r
e
a
dsa
ndo
f
f
t
he
s
he
l
fe
l
e
c
t
r
o
ni
c
swhi
l
eus
i
ngt
r
a
d
i
t
i
o
na
l
f
a
br
i
ctraditional
c
o
ns
t
r
uc
t
i
o
n
construction
tools
like
knitting
and
machines.
Using
ap
material-driven
approach,
ai
collection
t
o
o
l
sl
i
kekni
t
t
i
nga
nds
e
wi
ng
ma
c
hi
ne
s
.Usewing
s
i
ngam
a
t
e
r
i
a
l
dr
i
v
e
na
p
r
o
a
c
h,ac
o
l
l
e
c
t
i
o
no
fs
i
ng
l
e
ns
t
a
nc
e
s of
single
instances
of“
fabric
interactions
ore
“soft
triggers”
that
explicitly
interpret
fabric
related
actions
o
ff
a
br
i
ci
nt
e
r
a
c
t
i
o
nso
r
s
o
f
tt
r
i
g
g
e
r
s
”we
r
ed
s
i
g
ne
d
a
ndpr
o
t
o
t
y
pe
dt
ha
te
x
p
l
i
c
i
t
l
yi
nt
e
r
pr
e
t
f
a
br
i
cr
e
l
a
t
e
d as
inputs
were
prototyped.
These
soft
triggers
were
designed
tol
essentially
work
with
physical
properties
a
c
t
i
o
n
sa
si
np
ut
.Th
e
s
es
o
f
tt
r
i
g
g
e
r
swe
r
ea
l
s
ode
s
i
g
ne
dt
os
pe
c
i
fic
a
l
y
i
nc
o
r
po
r
a
t
ephy
s
i
c
a
l
pr
o
pe
r
t
i
e
sl
i
ke
such
as
conductivity
ore
shape
ofo
the
other
objects
ast
at
way
ofo
creating
an
immediate
relation
we
i
g
ht
o
rs
h
a
p
eo
ft
heo
t
he
r
x
i
s
t
i
ng
b
j
e
c
t
sa
se
s
s
e
nt
i
a
l
o
h
e
i
rw
r
ki
ng
,a
s
aw
a
yo
fc
r
e
a
t
i
nga
n between the
user,
the
soft
and
their
surroundings.
i
mme
d
i
a
t
er
e
l
a
t
i
o
ntrigger
be
t
we
e
nt
he
us
e
r
,t
hes
o
f
tt
r
i
g
g
e
ra
ndt
he
i
rs
ur
r
o
undi
ng
s
.
The
soft
triggers
prototyped
are
proofs
ofn
concepts
representing
parts
or
units
of
possible
medium-specific
Thes
o
f
tt
r
i
g
g
e
r
spr
o
t
o
t
y
pe
dwe
r
ep
r
o
o
f
so
fc
o
c
e
pt
sr
e
pr
e
s
e
nt
i
ngpa
r
t
so
ru
ni
t
so
fp
o
s
s
i
bl
eme
d
i
ume-textile
interfaces
that
facilitate
an
active
engagement
between
the
user
and
her
surroundings.
s
pe
c
i
fice
t
e
x
t
i
l
ei
nt
e
r
f
a
c
e
st
ha
tf
a
c
i
l
i
t
a
t
ea
na
c
t
i
v
ee
ng
a
g
e
me
ntbe
t
we
e
nt
heus
e
ra
ndhe
rs
ur
r
o
undi
ng
s
.
Thus,
the
design
undertaken
was
successful
in
illustrating
methods
forf
creating
Thus
,
t
hede
s
i
g
np
r
o
c
e
s
sprocess
unde
r
t
a
k
e
nf
o
rt
hi
st
h
e
s
i
sw
a
ss
uc
c
e
s
s
f
ul
i
ni
l
l
us
t
r
a
t
i
n
gme
t
ho
ds
o
r
c
r
e
a
t
i
nge-textile
e
interfaces
that
are
specific
to
the
medium
of
fabrics
and
that
curiously
involves
the
users
in
a
dialogue
t
e
x
t
i
l
ei
nt
e
r
f
a
c
e
st
ha
twe
r
es
pe
c
i
fict
ot
heme
di
umo
ff
a
br
i
c
sa
ndt
ha
tc
ur
i
o
us
l
yi
nv
o
l
v
e
dt
he
i
rus
e
r
si
na
with
their
immediate
environment.
di
a
l
o
g
uewi
t
hhe
ri
mme
di
a
t
ee
nv
i
r
o
nme
nt
.
Keywords
Keywords
Electronic
textiles,
fabric
interactions,
knitted
fabrics,
ludic
design.
El
e
c
t
r
o
ni
ct
e
x
t
i
l
e
s
,f
a
br
i
c
i
nt
e
r
a
c
t
i
o
ns
,kni
t
t
e
df
a
br
i
c
s
,l
udi
c
de
s
i
g
n.
Acknowledgements
I would like to sincerely thank Katharina Bredies without whose guidance, support and
inspiration this project would not have been possible. I also thank Till Bovermann for
his valuable feedback and encouragement through the writing process. I would like
to extend a special mention to Rosan Chow for giving me interesting reading material
and helping with the beginning of the thesis. I am deeply grateful to Raija Jokinen for
her enthusiasm and interest in the project, for helping me with my numerous knitting
questions and also for kindly giving me access to the knitting studio in the textile
department. My appreciation also goes to Anna Leinonen for her patience and help
while using the industrial knitting machine.
I am thankful to Markku Reunanen, Michihito Mizutani and Rasmus Vuori for sharing
their insights regarding my work at various stages of the project. A big thanks also
to my colleagues Jonathan Cremieux and Gokce Taskan for reading and commenting
on the text; and Liisa Tervinen and Lauri Kainulainen for testing the prototypes. I
also thank Pipsa Asiala, for her encouragement through the thesis process; and Ilpo
Kari and Heikki Tuononen, for their technical help. I would also like to convey my
gratitude to Eila Hietanen who helped me print this document.
Finally, I am heartily grateful to my parents for their love, patience and support.
5
Table of contents
1. Introduction
1.1. Thesis overview
1.2. A brief history of electronic textiles
8
9
10
2. Motivation for this study
13
3. Fabric as a medium for electronic interfaces : Defining problem areas or identifying opportunities
16
3.1. Looking at related work: Types of fabric interfaces
16
3.2. Taking forward the Insights gained from my previous work in e-textiles
21
3.3. Critical thinking, ludic engagement and e-textile design
22
4. Research questions
25
5. Assumptions
26
6. Working with knitted soft triggers
28
6.1. Production goals
7. Process: Working with knitted fabrics and electronics
30
32
7.1. Building a reference base
34
7.2. A technical approach to fabrics
37
7.2.1 Digital and analogue fabric switches
37
7.2.2 Working with physical properties of other objects
38
7.3. Generating ideas and concept sketches
39
7.3.1 Translating fabric related actions into triggers
39
7.3.2 Working with ‘states’ of fabric objects
40
7.3.3 Using scenarios and use-contexts as starting points
40
7.3.4 Working with interaction methods
41
7.4. Materials and tools
43
7.5. Prototyping
47
7.5.1 Knitting-drawing and circuit-planning 47
7.5.2 Power supply
49
7.5.3 Stitching the knitted parts together
50
7.5.4 Thinking about output indication for triggers
50
7.5.5 Designing the micro-controller unit
52
7.5.6 Testing, troubleshooting and programming
53
8. Results
54
54
8.1. Gallery
9. Summary of insights from the production process
76
10. Reflection
82
10.1. Looking at key factors that affected the design and attributes of the knitted soft triggers 82
10.2. Observations from a preliminary analysis of the soft trigger prototypes
84
10.2.1 Insights from finding different ways to activate the soft triggers in a home scenario
84
10.2.2 Observations from giving the prototypes out to others
86
90
10.3. Reviewing the prototypes in relation to the research questions
11. Discussion: Space for user re-interpretations in e-textile design
93
12. Conclusion and future development
96
References
Appendices
99
102
soft triggers
Appendix A – Feedback from interacting with
102
Arduino and Processing sketches used for testing
Appendix B –
106
Appendix C – DVD with video documentation of soft triggers
110
1. Introduction
Electronic Textiles or e-textiles is a new and upcoming field that aspires to integrate
textile materials with electronic and computational elements.
E-textiles incorporate capabilities for sensing (biometric or external), communication
(usually wireless), power transmission, and interconnection technology to allow
sensors or things such as information processing devices to be networked together
within a fabric. This is different from ‘smart textiles’ that features scientific advances
in materials research and include things such as better insulators or fabrics that
resist stains. E-textiles usually contain conductive yarns that are either spun or
twisted and include some amount of conductive material (such as strands of silver
or stainless steel) to enable electrical conductivity. (Berzowska, 2005a)
The researchers of e-textiles, as articulated by Leah Buechley (2006) strive to
ubiquitously incorporate off-the shelf electronics and other fabric-friendly conductive
materials such as conductive inks and threads in traditional fabric materials to
create soft and comfortable devices. They may be wearable but also seek inspiration
from wall hangings, quilts and other pervasive fabric-based artefacts.
The possibilities of electronic textiles to enter our lives seem almost as wide as
there are fabric artefacts in our everyday surroundings. The last decade has seen
a rise in e-textile products and research. Creative practitioners have adopted these
techniques to create interactive garments and furniture. The vast cultural and
social history of fabrics opens out multiple opportunities for designers and artists
to reinterpret the existing interactions and the common understanding of fabric
properties as means for digital interfacing. Wearable e-textiles allow little bits of
computation to occur on the body (Berzowska, 2005a). This has enabled researchers
to monitor the body of the wearer and its surroundings for medical (e.g. Cunha et
al., 2010) and military purposes (e.g. ISN/MIT, 2002). Other wearable e-textile
projects reinterpret clothes as assisting or reflecting on the social interactions of
the wearer ( e.g. Berzowska, 2005) or even as musical instruments ( e.g. Grant and
Grant, 2010). Some fabric artefacts such as tablecloths or wall hangings have also
been reinterpreted by designers to create new forms of expressive and interactive
displays.
8
The ability to embed computational elements or interactivity into textile products
that are integral to our environments, has been seen by some designers and
researchers as an opportunity to introduce another layer of meaning that aims at
enriching our experience of the everyday. This layer of meaning has taken the form
of additional electronic functions given to an otherwise traditional clothing, for
instance a coat zipper (Jennifer, 2011) that controls the volume on the wearer’s mp3
player. This meaning can also be for a more evocative realm such as a tablecloth
that reveals the patterns of everyday (Gaver et al., 2006), thus expressing a point
of view or bringing forth behaviours that are otherwise less apparent. In both of
these cases, e-textiles have been used to enhance or record experiences through
computation embedded in fabric materials. Thus, the medium of e-textiles presents
an opportunity to take a closer look at fabrics in our everyday lives and to explore the
potential of reinterpreting them as a medium for electronic interfacing and create
new experiences and interactions.
1.1.
Thesis overview
This thesis builds on the idea of exploring new interactions by investigating the role
of fabric as a medium for interfaces. It investigates the different ways to create fabric
interfaces by translating fabric properties into electronically readable signals while
enabling, through interaction, an active and creative relationship between the users
and their surroundings. Although exploring and deriving from textiles in general,
the practical process deals specifically with knitted fabrics. Using knitting yarn and
conductive threads combined with basic electronic components, various concepts
for fabric interfaces that essentially need other objects from their surroundings to
work were designed and prototyped. The thesis project was thus an in-depth study
of the different materials, as well as a play with reinterpreting gestures, actions and
scenarios associated with fabrics.
The thesis can be divided into three main categories. The first part describes the
context of work and the areas of enquiries that led to the production process. The
second part gives an in-depth report of the production goals and the practical design
process, while the third part presents the results of the production process followed
by discussing my reflections and findings.
The first part of the thesis is included in the first five chapters. First, I give a brief
overview of the history of e-textiles followed by explaining my background and how I
became interested to delve deeper into my thesis subject. I describe how researching
other works and publications in the field of e-textiles and looking at my previous
9
projects, helped me to identify some key problem areas or interesting aspects of
fabrics and electronics that I wanted to investigate further. I also articulate the main
research questions and the assumptions that guided the production process.
The second part, chapters 6 and 7, describes the hands-on approach taken to
practically examine and investigate the research questions raised. The decision of
working with soft triggers is explained and the production goals are listed. Chapter
7 gives a detailed account of the various steps and approaches taken to design and
prototype various soft triggers.
The third part consisting of chapters 8 to 12 presents the results and insights gained
from the production process. It illustrates the various fabric prototypes and relating
soft components that were designed and tested through the process. The main
findings from working with knitted fabrics and electronics are listed, followed by
discussing my impressions about the project as a whole. Chapter 10 analyses and
compares the different soft prototypes designed while also attempting to tackle the
research questions. In Chapter 11, I raise some open questions regarding e-textiles
and their potential for designing semi-ambiguous interfaces that could encourage
play and user reinterpretations. I conclude with Chapter 12 and describe my visions
for the future developments of the project.
1.2.
A brief history of electronic textiles
The field of e-textiles is only a little more than a decade old. It primarily branched out
of the research on wearable computing or ‘wearables’ which developed in the 1970s
and 1980s propelled by the works of prominent researchers like Steve Mann, Mark
Weiser and Thad Starner (Rhodes, 2000). The main focus of wearable computing was
the development and prototyping of new techniques of human-computer interaction
for body-worn applications (MIThril, 2003). However, these wearable computers
were often hard, obtrusive and found to be uncomfortable by users. The wearable
computers needed to be less fragile so that their users could wear them without the
fear of damaging the equipment. (Berzowska, 2005a)
In 1997, a design collaboration between the students and faculty of Creapole Ecole
de Creation (Paris) and professor Alex Pentland (MIT, Boston) produced the ‘Smart
clothes fashion show’, with the goal of envisioning the impending marriage of fashion
and wearable computers. (Rhodes, 2000)
10
The first breakthrough in e-textiles came with the development of a conductive
fabric which was silk organza that contained two types of fibres, namely plain silk
thread woven with a silk thread wrapped in thin copper foil. Wearable computers
then aspired to be merged seamlessly into ordinary clothing. Using various
conductive textiles, data and power distribution as well as sensing, circuitry could
be incorporated directly into wash-and-wear clothing. Passive components could be
sewed on fabric whereas others could be soldered directly on to the metallic yarn.
(Post and Orth, 1997)
Textiles have mechanical, aesthetic, and material advantages that make them
ubiquitous in everyday use and industrial applications. The woven structure of
textiles and spun fibres makes them durable, washable, and conformal, while their
composite nature affords tremendous variety in visual and tactile textures. (Post,
1999)
While the materials needed to be further developed for the fabric medium, the
earliest projects such as the ‘Firefly dress’, Music jacket with embroidered
keypad and electronic tablecloth in the early 2000s (see Figure 1) already started
exploring designs that incorporated different production techniques (industrial
and handmade), materials (different conductive fabrics) and ways of translating
electronic circuits to be seamlessly integrated with textiles (Post, 1997).
Figure 1. Early e-textile projects
(Left) Firefly dress. (Centre)
Music jacket. (Right) Interactive
tablecloth.
While focused research started to be conducted for military, medical and other
telecommunications purposes at the beginning of the century, other researchers
like Leah Beuchley worked towards creating kits and components to make working
with e-textiles more accessible (Buechley, 2006). The ‘high low tech group’ at
MIT Media Lab led by Buechley and the ‘XS labs’ founded by Joanna Berzowska
also published various techniques and explorations for integrating fabrics and
electronics (Buechley and Eisenberg, 2007; Berzowska, 2005a).
In 2008 the development of the ‘LilyPad Arduino’, a fabric based construction kit
that enabled novices to design and build their own soft wearables and other textile
artefacts (Buechley, Eisenberg, Catchen and Crockett, 2008), truly expanded the
11
scope of e-textiles by bringing it to designers and amateurs. With the easy availability
of conductive yarns and fabrics in smaller amounts for non-industrial uses, Lilypad
as an affordable sewable micro-controller opened out many possibilities for the
growing community of electronic-textile enthusiasts, .
E-textiles research and projects have thus in a short time gained momentum in
academic, commercial, artistic as well as experimental spheres.
12
2. Motivation for this study
Being a tangible interface designer, I was very familiar with working with electronics
and physical computing. However, my first proper encounter with using textiles with
electronics came during an internship at the Deutsche Telekom Laboratories in
Berlin in Fall 2010. There, I worked extensively with fabrics and designed interface
concepts for this medium under the supervision of doctoral student Katharina
Bredies. During the three months, we designed and prototyped a wearable fabric
controller called the ‘Music sleeve’ used for playing music on a mobile device
(Gowrishankar, Bredies and Chow, 2011). Not only did I get interested to explore
e-textiles further but working on this internship project also gave me invaluable
practical and conceptual insights about the medium which I saw as a very engaging
outlet for my interest and experience in tangible interactions.
Tangible interactions has been my key area of interest and enquiry through the past
few years. Working under the larger theme of studying people’s everyday physical
and emotional interactions with electronic objects, I find it intriguing how objects get
personified or reinterpreted by their owners. I strive to understand this relationship
with respect to the qualities it embodies and also how this relationship affects or
defines the nature of our immediate environment.
Reinterpretations and reuse of objects beyond their intended functions by their
users is well-established (Brandes and Erlhoff, 2006) although not fully accounted
for in the design process. Traditional Human-computer interaction (HCI) studies
believe that although the interpretations of a technical or electronic object could
be various, there should be just one intended clear purpose for a designed object.
However there are also discussions that counter argue this traditional view (Sengers
and Gaver, 2006). It is curious how the objects by their very nature take on different
roles; roles they play due to their physical properties, their functions or their sociocultural background. All things have the potential of playing more than one role. For
example in high school I had a calculator in which the zero button stopped working,
so to calculate with numbers that contained a zero, I had to find other ways by adding
or multiplying non-zero numbers to get the required result. In the traditional design
sense, this calculator would be non-functional, but for me this broken calculator
had acquired a personality that usually made the experience more interesting while
sometimes also being difficult to deal with. Either ways my calculator was unique,
13
it was something I could laugh or complain about while also getting my task done.
Over the years I have noticed many such objects that gained or established a
relationship with their owners and their surroundings on the account of some
strangeness or uniqueness they possessed. For example, in my under graduation
years, I purchased an extra plastic low-cost table fan to deal with the hot summer
in South India. When I plugged it in the first time, I discovered that the table fan
had such a light-weight body that when switched on it moved around with its own
momentum and motor vibration. Thus, after being switched on for 5 minutes, the fan
would have travelled about 20 cm and be pointing away from me towards a random
direction to the far end of the room. Depending on the situation, I had to either put
some more weight on this free spirit of a fan to keep it in one place or continue to
move with the fan to be always in the wind direction.
While being playful, the fan made me think about the production and design of
such goods and the compromises one makes in engineering or design while meeting
the need for low-cost products that are produced knowingly or unknowingly with
“imperfections” that can be easily overcome by the users. At the same time these
products escape much responsibility of functional reliability by playing on the
general low expectations people have from cheap goods. Not going into further
discussion regarding this, I would just like to highlight that the fan surely made me
raise some questions and created a dialogue.
Inferring from these small experiences, domestic electronic objects were found to
have the ability to question, provoke, be opinionated, satirical or to embody any such
characteristics or roles in one’s everyday life. Looking at it from a design perspective
it is interesting to explore ways of inducing this kind of “strangeness” into technical
objects as part of the design process to encourage creative dialogue between the
user, the object and their surroundings. Advocating the use of ‘strangeness’ in a
design process is not to say that one should make broken things or use this an excuse
for bad design, rather it is a study of relationships and designing a possibility to
reflect and respond to these relationships while performing everyday tasks.
I was thus interested in investigating how to design interactions that allowed for
reinterpretations by users and engaged them in a playful yet critical manner through
tangible interfaces. E-textiles proved to be an apt medium to tackle the enquiries
explained above: While working with e-textiles for the internship, we discovered the
natural potential of e-textile artefacts for being curious and unfamiliar. As I dabbled
with the new conductive soft materials and tools to experiment and prototype, the
contrasting nature of fabrics and traditional electronic components started becoming
apparent. It was common that the ideas we had on paper would fail when actually
constructed with the soft fabric material. Thus prototyping at every stage helped
us to understand the materials better. I found working with fabrics inspiring and
14
challenging. During this process numerous fabric artefacts were conceptualized that
adopted curious forms and textures as a result of attempting to efficiently integrate
the two contrasting materials. What resulted was a fabric interface that was born out
of technical requirements of the materials and acquired a unique aesthetic quality.
(Gowrishankar, Bredies and Chow, 2011)
This unfamiliar and unique quality of the fabric interface created during the
internship and the design process involved, provided an opportune lens to look into
new interactions and a glimpse into designing for intuitive, explorative and context
driven interpretations. Hence, I wanted to delve deeper and understand this quality
of e-textile artefacts and continue to experiment with them. The approach taken
during my internship that focused on fabric properties and interactions as the main
inspiration for interface designs, was also a valuable learning experience. For this
thesis, I was keen on taking further my skills in constructing and handling knitted
fabrics along with following the process of sketching and prototyping as an integral
part of the concept development and design. This was an interesting area to delve
into because it involved readily available materials like regular textiles, conductive
yarns and traditional electronic components which made it easily approachable.
The field of e-textiles or ‘wearables’ is fast growing and it is exciting to be a
part of this upcoming community. With this work, I also wished to contribute to
the methodologies and knowledge in this new field. Hence, I saw this thesis as
an opportunity to not only develop my skill sets and understanding of fabrics to
work with e-textiles but to investigate its relevance to interaction design and lay a
foundation for my future work in the field.
15
3. Fabric as a medium for electronic interfaces :
Defining problem areas or identifying opportunities
The techniques and methods required to use e-fabrics as a new medium for
electronic interfaces are being actively developed. The following sections give an
overview of the problem areas or rather opportunities that were explored through
this project. They were identified through studying and sorting related works in the
field of e-textiles, drawing from my own experiences in working with fabrics and
electronics and importantly, looking at how alternative and critical approaches to
traditional HCI can be studied through the process of designing e-textiles.
3.1.
Looking at related work: Types of fabric interfaces
A wide spectrum of projects surfaced from delving deeper to find previous works done
in the field of e-textiles, from research projects involving clothes and wall hangings
that could change their physical appearance or enable the user to communicate
with people around, to commercially available health monitoring wearables and
mp3-incorporated jackets. They are better explained in the following paragraphs.
There were also many smaller experimental projects from amateurs and enthusiasts
interpreting gestures (e.g. Rowberg, 2011) or designing soft musical instruments
(e.g. Grant and Grant, 2010). While some projects tried to investigate and assist the
future of e-textiles (e.g. Buechley, 2006), others were playful explorations of forms
and interactions.
A qualitative analysis of all the projects involving e-textiles showed that the specific
role played by fabrics in the interface concepts could be broadly divided into three
main categories. The first kind were interfaces that used fabric as an underlying
layer or a substrate to mount other electronically active components. The second
type used fabrics as means for output and the third incorporated fabrics as sensors
or switches that acted as the input for a system. These categories are explained in
detail below:
16
1. Fabric as substrate:
These interfaces or e-textile objects treated the fabric as an underlying surface
over which electronically active elements were mounted. These were electronic
components like light emitting diodes (LED), different kinds of sensors, speakers
and other such devices. The circuit design aspired to complement the nature of
the fabric to efficiently distribute the components across its surface but did not
use the fabric itself as a component of the circuit.
It was found that most of the industry led innovations had taken this approach, taking
advantage of the fabric being present in our environment by directly embedding
another layer of electronics on them. The field of fashion has numerous projects that
use fabric as substrate and use lights or sound as expressive elements placed on top
of it. The interactive dress ‘Klight’ (see Figure 2) by fashion designer Mareike Michel
and Fraunhofer IZM in 2008 (stretchable circuits, 2008) is one such example. The
dress has miniaturized electronic modules and LEDs mounted on a flexible printed
circuit board made specially for using with fabrics. The movement of the wearer is
detected by a sensor and translated into light patterns illuminated by the LEDs (ibid.). Figure 2. Klight dress. Design
The flexible circuit board represents a typical development in the field of e-textiles by Mareike Michel, 2008.
that attempts at a more seamless integration of electronics into fabrics by designing
‘soft’ versions of the traditional electronic components.
As fabrics are wearable and stay close the body, different kinds of sensors could
be mounted on them for medical purposes such as electrocardiography (ECG)
or other health monitoring systems. The heart rate monitor sports bra developed
by NuMetrex (see Figure 3) is a commercially available product that measures
the wearer’s heart rate and sends the information to a computer or a compatible
wrist watch (NuMetrex, 2005). Some professional clothing also used fabric as
substrate to embed capabilities to assist the wearer with her work. The clothing
designed by VIKING for the safety of the firefighters have thermal sensors that
visually indicate critical heat levels on the display unit integrated on the sleeve
of the jacket (Eric, 2008).
2. Fabric as output:
Figure 3. Heart monitoring
sports bra from Numetrex.
The e-textile interfaces that used fabric as output were those in which the
fabric material physically changed in shape or appearance as the result of an
interaction. ‘Kukkia and Vilkas’ (see Figure 4) by Berzowska and Coelho are
two animated dresses that use the shape memory alloy Nitinol to move or change
shape over time by resistive heating and control electronics (2005).
17
Some interfaces used the textile surface as a display by physically changing its
colour or pattern with interaction. ‘Shimmering flower’ (see Figure 5) by Joanna
Berzowska was one such example of a non-emissive colour changing display that
could be programmed to slowly change its pattern and colour over time (2004).
Figure 4. (Left) Kukkia and
Vilkas: Kinetic electronic
garments.
Figure 5. (Right) The
shimmering Flower: Colorchanging textile display.
Since textiles have a prominent yet silent presence in our surroundings, various
e-textile projects have interpreted the fabric medium to mirror everyday
occurrences and used it to physically reveal relevant patterns. They were found
to be superimposed into our everyday and did not demand direct physical
interaction. Instead, they involved the user on a more emotional or evocative
realm. Their presence in an environment already ‘activated’ them. The ‘History
Tablecloth’ (Gaver et al., 2006) collects data from load sensors placed at the
corners of a table to illuminate relevant portions of the history tablecloth
draped on the table (see Figure 6). The tablecloth itself was silk-printed with
an electroluminescent material. When objects were left on the table, the portion
of the tablecloth beneath them lighted to form a halo that grew over a period of
hours, highlighting the flow of objects in a household. (Gaver et al., 2006)
Projects like ‘Pure Play’ (Berzowska, 2005) (see Figure 7) and ‘Feathery
Dresses’ (Berzowska, 2005) (see Figure 8) in the Memory Rich clothing series
interpret body heat and touch by using thermochromic ink applied on parts
of clothing and LEDs respectively. Thus, in the above mentioned projects,
the fabric changed its appearance to give a visual or tactile feedback to an
interaction with the system.
Figure 6. (Left) The history
tablecloth: Illuminating
interactive fabric.
Figure 7. (Centre) Pure Play:
Heat sensitive colour detail.
Figure 8. (Right) Feathery
dress: Touch sensitive garments.
18
3. Fabric as input:
This category included objects or clothing that incorporated fabrics by using
them directly to generate the electronic impulse responsible for the output of
the system. They used fabrics as sensors or switches that operated the system.
The nature of interactions were various but they involved direct physical
contact with the fabric ‘components’. The website ‘www.Kobakant.at’ by PernerWilson and Satomi (2007) has an extensive online database of various sensors
and switches made with fabric materials. Its authors explore different ways to
incorporate conductive threads and fabrics to create sensors that react to touch,
pressure and other such interactions.
There are also fabric explorations like Joypad (Perner-Wilson, 2008) (see
Figure 9), Joyslippers (Perner-Wilson, 2008b) (see Figure 10) and Felted Signal
processing (Grant and Grant, 2010) (see Figure 11) that use fabrics to measure
pressure and stretch applied during interactions as an input for generating
different results. Joypad uses punching and pressing a round soft disk made
of fabric whereas the Joyslippers interpret feet movements. The project from
Felted Signal Processing find ways of creating interactions with long soft tube
of felted wool.
Figure 9. (Left) Joypad: Fabric
interface for controlling mouse
movement on screen.
Figure 10. (Centre) Joy slippers:
fabric weight-sensing shoes
Figure 11. (Right) Felted stroke
sensors from Felted signal
processing
These interfaces used fabric properties such as softness or flexibility to interpret
the physical interactions as switches or triggers to generate an output. These
interactions mostly involved some amount of play and the feedback loops were
quite quick. They were mostly designed to be controllers for games or for video
and audio manipulation.
Fabrics should be the focus of interaction design in e-textiles as it is the textiles that
makes them different from other electronic interfaces. A lot of the e-textile products
try to imitate existing electronic circuits and components onto fabrics, for example
making a traditional PCB flexible. However, using fabric itself as an element of
interaction was felt to be largely unexplored.
Looking at the above mentioned categories of how fabrics have been incorporated
in e-textile interfaces revealed that not all approaches fully take into account the
medium of fabrics in their designs. The interfaces that use fabrics as substrate
19
were concerned mainly with efficient distribution of electronic components over an
existing piece of fabric thus only passively involved the medium. The ‘fabric as
output’ group usually used inks and memory alloys to respectively change colour
and shape in addition to the material of fabrics. E-textile researchers strive to
build devices that are as soft, flexible and comfortable as traditional cloth artefacts
(Buechley and Eisenberg, 2007). However, not many have tried to use the existing
language of fabrics as key inspiration for designing these devices. One sees that a
Figure 12. Ralph Lauren RLX
large portion of projects and ideas relating to e-textiles follow previous trends in
Aero Type Jacket. (Image from
technabob.com/blog/2010/01/02/ wearable computing rather than analysing the true nature of the medium. They only
wired-ralph-lauren-aero-typetry to change the face of existing technologies to be mounted on fabrics rather than
ski-jacket/)
taking this opportunity to really explore fabric properties to create novel digital
artefacts that could enrich and expand our experience of everyday life. For example
the ski jacket designed by Ralph Lauren (Technabob, 2010) that incorporates an
mp3 controller in its sleeve relies on the same interaction as the existing player (see
Figure 12) as it directly copies the traditional music interface onto the sleeve of a
jacket. Although it uses revolutionary technologies, this e-textile product misses the
possibility to truly reinterpret the fabric for creating a new experience of skiing and
listening to music.
The category of interfaces that were found to have truly attempted to design
specifically for the medium of fabrics was the third one: ‘fabric as Input’. These
projects incorporated fabric as an element for direct interactions and used the
familiarity of textiles as a motivation behind these interactions. For example the
soft pressure sensor (see Figure 13) is a felted soft ball that senses the pressure
applied on it. Being of a familiar form and soft material, squeezing it in your palm
comes as a natural interaction. Thus, the fabric itself acts as the sensor or switch
that activates a system.
Figure 13. Soft pressure sensor
from http://www.kobakant.at/
DIY/
20
These interface concepts did not only provide a fresh outlook to fabric oriented
interface design but also aspired to create fabric-made sensors by reinterpreting
existing electronic components such as a pressure sensor, using materials and
techniques from the tradition of fabrics. Following a similar approach to the projects
of Hannah Perer-Wilson and Mika Satomi, using fabrics as input was seen as an
important opportunity to delve deeper into the ecosystem of actions and scenarios
relating to textiles to translate them into interaction elements. It was felt that these
interaction elements made from fabrics act as the building blocks for creating truly
soft-devices.
3.2. Taking forward the Insights gained from my previous work in
e-textiles
I have used the inferences and reflections gained from my internship as a starting
point for my thesis. Being my first encounter with e-textiles, I gained important
material and procedural insights about working with fabrics and electronics that
opened a door for further enquiry. One such important discovery was the contrasting
natures of fabrics and electronics. Both media have very definitive characteristics
behaviourally, and also come with specific tools and context. Sewing machines,
needles, knitting machines, soldering irons, pliers etc. have specific functions in
their traditional environments. Electronics require tight connections, good contact,
and insulation for a reliable circuit. Fabrics inherently possess qualities that are
light, fluid, easily influenced by the shape and nature of objects around them. Trying
to integrate electronic components, originally made for stiff circuit boards to be
screwed and sealed inside a machine, with fabric materials that are soft and versatile,
posed a curious challenge. It was often found that attempting to compensate for
this contrast in materials led to unusual forms and interactions. Therefore it was
recognized that there was a potential to generate interesting results in working with
this incompatibility rather than to pacify it.
Another important observation from the internship work was regarding the
inefficiency of fabrics to always solely meet the requirements posed by electronics.
Textiles, being light and susceptible to the environment, caused the circuitry to be
largely unreliable, often having insulation or connection problems. While thinking
about fabric interface elements, one almost always needed to find conductive
objects related to fabrics that could be stitched on as part of the soft circuit to
help the electronics to function properly (e.g. metal snap buttons to connect or
disconnect soft-circuits easily and reliably) (see Figure 14). Although one tried to
stick purely to fabrics as much as possible, it became apparent that some assistance
from external conductive objects was more often than not a necessity. This created a Figure 14. Using metal snap
bridge between the e-fabric artefact and the context it came from. In the beginning buttons to make reliable
connections.
this meant using conductive objects like buckles, zippers or metal buttons which
were usually used in garments or accessories made from fabric. But the related
conductive objects could also be extended to a larger context that involved objects
from common use-cases. For example using metal cutlery and vessels with a table
cloth or cloth clips and laundry baskets in the washroom. This provided an exciting
opportunity to actively involve different fabric related contexts and environments
into the design process.
Establishing that fabrics and electronics were contrasting as a constraint stretched
the design process to go beyond the initial tendencies to imitate traditional electronic
circuits. An in-depth understanding of the constraints and opportunities laid by
21
fabric and electronics were needed to find unconventional ways in which they could
be juxtaposed.
The intrinsic nature of fabrics to work with other objects was identified as an
opportunity for purposefully incorporating other objects from one’s surroundings in
a meaningful way. There was also a possibility to use this incapacity of fabrics to
meet the electronic requirements as a concept for design rather than trying to find
ways to hide it at the cost of losing the ‘fabric-ness’ of the e-textile objects.
3.3.
Critical thinking, ludic engagement and e-textile design
The field of e-textiles aspires to create artefacts and experiences in our everyday
lives. Every new domestic technology is changing our behaviour, expectations and
patterns. As technology enters every aspect of our lives, it is no longer a separate
entity but rather a way of life. As the users get more varied with minute differences in
their everyday lives, there is a need for more flexible systems that adapt to different
scenarios. While design embraces new technologies, notions of society and time,
it does not always reflect upon itself and the changes and effects it brings about in
the micro and macro levels of users, their lives and the surroundings. Dunne and
Raby (2001) while talking about the approach designers take towards electronic
objects point out that the introduction of Sony Walkman in the early 1980s offered
people a new kind of relationship to urban space. It functioned as an urban interface
by providing a soundtrack for travel through the city thus encouraging different
readings of familiar settings. After so many years, today there are many variations to
the original walkman but the relationship it created to the city remains unchanged
(Dunne and Raby, 2001, p.45). The walkman enabled people to reinterpret their
surroundings. It enhanced the concept of mobility and used it to create a new kind
of interaction that extended the perception of an urban landscape. However the
designs and technologies for portable music players following the walkman have
only changed in appearance, interface, formats but have not attempted to reinterpret
the relationship it created with the surrounding environment.
In design, the main aim of interactivity has become user-friendliness. Although
this goal is important in the workplace for improving productivity and efficiency,
Dunne (2005) expresses his concern towards the assumption that closing the gap
between humans and machines or designing “transparent” interfaces would be
key to humanizing technology. He believes it to be problematic, particularly as
this view spreads to the less utilitarian aspects of our lives. He further claims that
user-friendliness helps to neutralize electronic objects and the values they embody
22
thus constraining people to the conceptual models, values and systems of thought
embodied by the machines they use. Rather than closing the gap between the user
and her machine, Dunne suggests poeticising the distance between people and their
electronic objects to encourage sensitive skepticism instead of only supporting
consumeristic goals. Coining “critical design” Dunne and Raby (2001, 2002)
have designed series of conceptual artefacts that stimulate discussion and debate
amongst designers, the industry and the public about the aesthetic quality of our
electronically mediated existence. Although sometimes their arguments can seem
manichaean, their objects are not. The critical design artefacts are alternative and
often provocative and set out to engage people through humour, surprise and wonder
(Dunne and Raby, 2001).
While critical design focuses on creating “value” fictions through artefacts, ‘Ludic
design’ developed by William Gaver follows a similar pursuit of questioning the
all-utilitarian perspective of HCI studies by bringing forward elements of play and
curiosity into interaction design. Ludic design is based on the notion of designing
for homo ludens– people as playful creatures. It identifies a home as not only a place
for accomplishing utilitarian tasks like cooking dinner or adjust heating but also a
place for less task-oriented activities like reading, playing games or pursuing idle
speculation (Gaver, Bowers, Boucher and Pennington, 2004). It highlights that such
activities are not simple matter of entertainment or wasting time, and on the contrary
they can be mechanisms for developing new values and goals, for learning new things
and for achieving new understandings. Ludic design recognizes the importance of
developing domestic technologies that reflect both utilitarian and ludic values and
an existing demand for products that support curiosity, exploration and reflection.
Supporting ludic engagement may counterbalance tendencies for domestic
technologies to portray a home as little more than a site for work, consumption and
relaxation. (ibid.)
Although ludic design is more playful, both critical and ludic design aspire to create
a space for reflection and wonder through artefacts that provoke the viewer or user by
their unconventional appearance or behaviours. Compared to critical design, ludic
design feels more approachable as it focuses on curiosity and reflection through more
active interaction where thoughts, ideas and narratives surrounding the ludic design
unravel and grow with more active exploration. However, both design practices take
some common approaches for embedding the space for reflection in artefacts which
I felt were apt for the medium of e-textiles:
Critical design points to the importance of conveying the ‘suspension of disbelief’.
While being almost believable, the objects are designed to foreground the
underlying value fictions and create room for one’s imagination. Similarly, Ludic
design emphasises the methods of presenting the familiar as strange and the strange
23
as familiar and to avoid the appearance of a computer. Looking at e-textiles one finds
that fabrics are a new medium for creating electronic interfaces, thus the metaphors
for interaction have not been established or standardized like in the case of regular
electronic interfaces where we know what a play button looks like or how to interact
with a touch screen. Combining fabrics and electronics can thus result in strange
and curious artefacts that are made from familiar fabric materials but create space
for play and exploration through interactions that are not usually associated with
electronic interfaces.
Hence I felt that e-textiles, due to their inherent ability to play with familiar and
strange provide a space for creating ludic engagements. It also brought forward an
opportunity to explore and find methods to combine fabrics and electronics in an
effective manner to create engaging and curious artefacts that can enable a dialogue
and make room for critical thinking.
24
4. Research questions
The research questions extracted from the opportunities identified in the previous
section were as follows:
1. How to integrate fabrics and electronics to create electronic interfaces that are
specific to the medium?
2. How to translate the versatility and material familiarity of fabrics into electronic
interfaces that enable a dialogue, through interaction, between the underlying
artefact, the user and their environment?
Fabrics have been present for thousands of years and have adapted to the different
needs and lives of people. We interact with fabrics on a daily basis and understand
their material qualities. For example, we know how a light fabric would behave in
the wind or can guess quite accurately which fabric is good for a particular weather.
Everyone is familiar with textiles and understand their ‘language’ of forms and
affordances in common textile objects. For example, one can see an open piece of
cloth and deduce various ways in which to use its materials properties such as a
curtain to be hung on the window or to spread on the bed as a cover or tied across
two poles to make a cradle for an infant. Fabrics have been very versatile and deeply
rooted ‘interfaces’ in our lives with a strong foundation of an enormous materialknowledge base, construction techniques and a long history of uses and scenarios.
When using fabrics as a medium for designing electronic interfaces, it was felt that this
vast traditional and practical knowledge of textiles should be key to the interaction
design concepts. Since fabrics were central to the interface concepts, techniques and
methods needed to be explored to design interactions that related directly and were
specific to the medium of fabrics. For example an electronic interface that interprets
a common action like folding up a sleeve as an interaction element uses the material
quality of fabric – it can be folded or crunched up – while also interpreting the
behavioural gesture of folding up one’s sleeve. It might also evoke other associations
such as situations when one folds up their sleeves when its warm, when relaxed or
getting ready for something.
25
Figure 15. Wiffinder™ 310
Backpack from Soyntec. (Image
from http://www.soyntec.com/)
However, a bag that displays the availability of wifi networks (see Figure 15) is simply
a display integrated into the surface of the bag. Its an electronic module that could
have been on any surface like a cardboard cover of a book or part of a cycle frame.
The design of the module does not take advantage of being on the soft material of the
bag, and in fact it also overlooks the interaction by placing the visual indicator on
the back of its wearer where it wont be seen. Thus it is clearly not as specific to the
medium of fabrics as the sleeve in the previous example, although both devices are
examples of e-textile interfaces. Hence, the first research question relates to finding
methods and techniques in which fabric is central to the design of the interface that
it embodies.
The materials’ incompatibility between fabrics and electronics along with the
dependency of fabrics on other objects to function as a medium for electronic interfaces
(see section 3.2) led to the second research question. One needed to systematically
search for other objects within the context of fabrics that could help in the design of
reliable circuits while being inside the context of fabrics (e.g. using a metallic buckle
to connect two sides of a conductive belt). I felt this quality of the medium enabled
an entry point into the larger theme of designing for ludic engagement and provoking
playful interpretations and dialogues through tangible interfaces. Inviting a diverse
set of interpretations through fabric interfaces that intentionally involve other objects
in their surroundings could be a way to facilitate a creative dialogue. I also felt that
bringing forward this incapacity of fabrics to be compatible with electronics would
encourage its users to take the extra step and explore ways of bridging this gap,
thus creating a more engaging experience. The second research question aspires to
explore the more evocative realm by finding ways in which these soft devices could
facilitate an active relationship between the user and her surroundings.
5. Assumptions
The process of research and practical enquiry that was deployed to answer the two
research questions were based on the following assumptions. These assumptions also
closely guided the production process.
1. Electronic interfaces that take direct inspiration from our existing interactions
with fabrics and use material properties of fabrics as integral elements in their design
will lead to e-textile interfaces specific to the medium of fabrics.
26
With respect to the first research question enquiring the integration of fabrics
and electronics to create electronic interfaces that are specific to the medium,
can be achieved by keeping fabrics as the central focus of the design process.
By doing so, it was hoped that unique interactions and experiences which were
specific to this medium could be drawn. Both textiles and electronics have
very distinct characteristics, and it was assumed that listening to these specific
material needs would result in new and unexpected designs. The attempt was
to not enforce existing interface ideas onto the fabric medium but to derive new
ones directly from the material properties.
2. Traditional electronics when integrated into fabrics that are of a contrasting
nature result in digital artefacts that are transparent and unfamiliar.
These two media, each having a long history and presence in our everyday, when
juxtaposed could create a kind of perceptual tug-of-war of meanings. When
integrated to create an object, these combinations emit the properties of both
textile and electronics at different times. Though fabrics and electronics can be
merged together to an extent, the inherent conflict of their material properties
can not be completely hidden, giving these digital artefacts a transparency and
yet a strange unfamiliarity. It was assumed that this transparency would play
an important role in motivating the users to interact with the fabric objects thus
assisting the second research question of enabling a dialogue between the fabric
device and its users.
3. Designing fabric interfaces that use other existing objects as essential to their
working provoke the users to develop a diverse set of interpretations and associations
between the underlying artefact and its surroundings.
The second research question enquired about how to translate the material
properties of fabrics into electronic interfaces that enabled a dialogue, through
interaction, between the underlying artefact, the user and their environment.
One way to involve the surroundings of the user was assumed to be through
the objects that are present in her immediate environment. Fabric interfaces
that were designed specifically to respond to other objects would create a direct
relationship between the fabric artefact and its near-by objects. If the e-textile
artefacts relied on the physical properties such as conductivity, size, shape,
weight of other objects to function, they would encourage the users to explore,
reinterpret and adapt their immediate contexts differently in order to interact
with the fabric object. Thus interacting with the fabric trigger would also mean
interacting with other objects.
27
6. Working with knitted soft triggers
A hands-on approach was taken to test and analyse the assumptions stated in
the previous chapter. Although addressing the material of fabrics in general, the
practical part of the thesis focused specifically on working with knitted fabrics and
finding e-textile solutions that were specific to this medium. Knitting is a popular
activity with a unique aesthetic appeal that is soft, comfortable and approachable to
everyone. There are numerous knitting techniques that can be used to knit fabrics of
any desired shape or size. The different knitting structures not only form distinctive
visual patterns but also influence the texture and behaviour of knitted fabrics; for
example knitted fabrics with rib structures are more stretchable than single knit ones.
As a process, knitting is intricate, strategic and methodic. It has many variables like
yarn thickness, needle positions, knitting stitches that can be modified and combined
to accurately produce different forms.
Knitted fabrics were an appealing choice as they helped to focus the production
work on a particular material within the larger theme of fabrics and to generate
ideas specific to the medium of knitted fabrics. At the same time, the medium was
extensively versatile allowing for in-depth experimentation and learning. Knitted
fabrics also enabled easy incorporation of conductive yarns with normal knitting
yarns to form customized fabric surfaces. The decision of using knitted fabrics was
also an initiative to take forward the experience gained by working on the knitting
machine during my internship in Berlin (see section 3.2 on page 21).
Following the assumptions stated in chapter 5, an in-depth understanding of the
following was needed for creating medium specific e-textile interfaces that worked
with other objects:
1. fabrics in their ‘natural habitat’ and our everyday interactions with them to
reinterpret them as electronic interfaces.
2. the constraints, characteristics and opportunities presented by the materials and
the different construction tools to find efficient ways of creating soft devices.
28
3. the properties of surrounding objects like their weight, shape or conductivity
that a soft device could respond to as a way for creating a physical relationship
between the fabric interface and its surrounding objects.
Since my knowledge of fabrics and soft-circuitry was only at a basic level in the
beginning of the project, a hands-on experimentation was essential to practically test
the ideas sketched on paper. The everyday interactions with fabrics (1) were observed
and collected for fabrics in general and also specifically for knitted fabrics. A deeper
understanding of (2) and (3) were established through designing and experimenting
with single elements of interactions made from knitted fabrics, or what I call “soft
triggers”.
I define a soft trigger as an electronic artefact, made with fabric, that embodies a single
action-reaction relation. In this case the action is the actual physical interaction and
the reaction is the resultant change in voltage in the electronic circuit. Soft triggers
can be seen as singular instances of interaction that are the building blocks for a fabric
interface similar to sensors and switches of a regular electronic device. These have
the ability to be combined in different contexts and assigned appropriate functions for
creating more coherent interfaces or devices.
The soft triggers are thus parts of possible soft-devices that can be made from putting
these triggers together. Designing the smallest unit also meant that the nature of
interactions embodied by the triggers would be emitted in the larger coherent
interface that it would be part of. Being made from knitted fabrics, the soft triggers
gave an opportunity to fully explore and experiment with knitting methods and forms
for incorporating soft circuitry. Thus, working with these single instances of fabric
interactions allowed for quick tests and a broader range of explorations that focused
specifically on the medium and interactions relevant for the thesis. While they were
basic in their working, they provided enough complexity to produce a wide range of
explorations and iterations.
These soft triggers were designed and prototyped to study the materials and explore
different fabric related properties. The next section explains the goals established for
creating the soft triggers.
29
6.1.
Production goals
The assumptions made in chapter 5 stated that interfaces that incorporated fabric
properties would be specific to the medium and that involving surrounding objects
in the working of the interface would create a relationship between the user, the
electronic artefact and their surroundings. Designing soft triggers was a way to take
a closer look at fabric interfaces and tackling different aspects of knitted fabrics
and electronics individually and methodically by implementing the assumptions as
design guidelines for these triggers. The idea was to widely experiment and fully
exploit the properties of knitted fabrics through the design of many different soft
triggers that responded to other objects.
In this way, each knitted trigger was planned to be inspired from specific fabric
qualities, incorporated singular gestures or actions in accordance with the first
assumption. It addressed the contrasting nature of fabrics and electronics as stated
in the second assumption and was designed to respond to at least one other physical
property of other objects (such as their shape or volume) to encompass the third
assumption. Every working soft trigger made was a result of an intense iterative
process. An analysis of all the triggers created and the findings are described in
chapter 9 and 10. The production process was thus aligned towards finding practical
solutions to formalise these assumptions for further analysis and reflection.
In a nutshell, the goals behind the production process were to design knitted soft
triggers that:
1. explicitly interpreted fabric related actions as input. For example folding or
stretching.
2. incorporated physical properties like weight or shape of the other existing objects as
an integral part of the soft triggers and essential for their working.
Figure 16. (Right) Close-up of
fabric being knit on the knitting
machine.
30
31
7. Process: Working with knitted fabrics and
electronics
The overall thesis work spanned over nine months (see Figure 18). The practical work
was of a highly iterative nature often going back and forth between the various steps
as shown in Figure 17. One of the first steps was to create a reference base of common
interactions and properties associated with textiles for a basic understanding of the
medium. Since textiles were the central focus I also aimed at achieving an in-depth
understanding of knitted fabrics as materials for integrating soft circuitry. A handson approach was taken in which sketching and prototyping were important steps for
concept development. Learning to be proficient with construction and assisting tools
was also an integral part of this investigative process. This portion of the project
involved a material-driven production process with various soft trigger prototypes as
its outcome. The other aspect of the process involved evaluation of these prototypes
by relating them back to the everyday environments. A few of the triggers were also
given to some test users to keep and interact with for a few days. An overall review
Listing material
properties
Collecting visual
references
Mapping fabric
related actions
Building a fabric
reference-base
Ways of integrating
soft circuitry
Knitted fabrics +
conductive yarns
Figure 17. The different steps
involved in the thesis process
Working with
tools
Material
understanding
Giving it out
to see first
reactions
Sketching
Prototyping
Material Exploration
Building e-textile interface concepts
32
Knitting machine
E-textile related
Reflection
Fabric interface analysis
October
September
August
July
June
May
April
March
February
January
December
November
October
2011
September
August
2010
Internship at Deutche Telekom Labs, Berlin.
Master thesis idea presentation, Media Lab
Research
Background research + idea evolution
Reading, finding references + developing overall
concept
Production
Initail sketches
Figure 18. Time span for thesis
work.
Concept sketches for prototyping
Giving out knitted prototypes for initial reactions
Knitting and experimenting with electronics
Troubleshooting, documenting
Half a day trial using industrial knitting machine
at knitting factory, Otaniemi.
Reflection + Documentation
Writing
Masters thesis 2nd paper presentation, Media Lab
Paper presentation on e-textile project done for
internship at Nordes design research conference
Collation, documentation, book design
Thesis submission
pre-thesis e-textile work
single events
time periods
was conducted evaluating the properties and characteristics of the soft triggers which
was helpful to further the conceptual and practical understanding sought by the
research queries.
The production process can be explained best by dividing it into three main categories
(see Figure 19). The first was verbal and visual mapping of fabric properties followed
by brainstorming ideas through sketching and then prototyping the more “realistic”
sketches with a knitting machine. First I will explain the process of collecting
references followed by illustrating the technical factors that were important for
generating ideas. Further ahead, I highlight the nature and constraints presented by
materials and tools used, and finally explain the prototyping process in detail. I would
thus try to give an in-depth illustration of not only what was done but also how and
why it was done.
2.
1.
Collecting references
Idea generation
Sketching
Familiarizing
Visual + verbal
Understanding
mapping
basic
with the
electronics
properties and
constraints of
Learning to
materials and
incorporate
tools
other objects
3.
Prototyping
Knitting
+ Circuit
planning Figure 19. Three steps of the
production process.
33
7.1.
Building a reference base
The presence of fabric is immense in our everyday environment. A large percentage of
clothes we wear, the surfaces we sit on, touch or rest on are made from or incorporate
textiles. Fabrics are constructed and available in various shapes, sizes and textures.
Different textures are appropriate for different artefacts such as soft for a couch cover,
rough for a towel or stretchy for a shopping bag. We also interact differently with
different kinds of fabrics depending on the situations. A bed cover is folded when
not in use and spread out when being used. We knot the strings if they are on a
shoe and pull them if they are around the mouth of a bag. We wrap a scarf and twist
or squeeze wet cloth to remove the water; the examples are numerous. Building a
comprehensive reference base that contained and presented these different aspects
and interactions with fabrics in one’s daily life was seen as an entry point to designing
e-textile interfaces. This also became also the guidelines that the rest of the process
could align with.
Fabric substrates can be of different textures and made from different materials but
there are some properties like softness or versatility that are commonly associated
with textiles. Different fabrics are interacted with differently according to their form
and texture/material. With new technologies the actual material properties of textiles
is fast growing. However only fabric properties and actions in the traditional sense,
such as folding, stretching or pulling were recorded to gain a basic understanding.
A wide range of references were collected by following three kinds of fabric-mapping
approaches explained below:
1. Fabric interactions and properties
The first map listed the different actions and objects that gave an overview of
the everyday interactions with fabrics (see Figure 20). The purpose of this was to
get a high level view of different actions (e.g. folding and hanging), construction
methods (e.g. sewing and knitting) and tools used (e.g. sewing machine and
weaving looms) to start understanding the ecosystem of fabrics with respect to
interactions.
The map also included a list of fabric properties (such as soft, stretchy) and
thinking a bit further in the process, I also listed some common conductive
objects associated with fabrics that could be incorporated in the designs as a
part of soft circuits.
34
Figure 20. Mapping fabric
interactions and properties:
Mind map listing different fabric
properties and fabric related
actions, tools and construction
techniques.
2. Mapping perceptual or situational understanding
When working with (1) it was felt that although it gave a good overview of the
different interactions, the map of high-level fabric interactions was not always
sufficient. A closer look was needed at some of these interactions to understand
the different contexts and meanings they are commonly associated with. Working
from an interaction point of view, the perceptual maps (see Figure 21) were made
by listing fabric objects that are associated with a particular action and finding,
through everyday life observations, the common contexts and motivations behind
these actions. The physical gestures involved in each of these actions were also
included.
This exercise revealed interesting aspects of fabric interactions that could be
taken into account for concept development. For example the action of crumpling
a piece of clothing was many times followed by throwing and aiming or the fact
that sometimes more than one person is needed to interact with a piece of fabric
either because of its shape or size thus bringing in a social aspect to these
interactions. These insights were helpful further in the process as they enabled
sketches that were more like ‘instances’ rather than ‘objects’. In other words, it
helped to place or situate ideas in contexts and imagine use cases.
35
Figure 21. Perceptual maps of
fabric related actions.
36
3. Collecting Visual References
The process of mind-mapping textile interactions and associations was also
paralleled by finding visual references of the actions (see Figure 22). Collecting
images and photos of these actions and properties furthered the idea generation
process and enabled a richer web of associations.
Figure 22. Example of
visual references collected for
‘knotting’.
Keeping in mind the focus on knitted fabrics, visuals of knitted textures and
structures were also collected (see Figure 23). These were very helpful to imagine
and seek appropriate techniques used to achieve a desired texture.
Figure 23. Example of visual
references collected for fabric
textures.
7.2.
A technical approach to fabrics
While the association maps and visuals helped to paint an overview of everydaylife interactions with fabrics, a basic understanding of electronics was required for
practically translating initial e-fabric interface concepts into ‘workable’ sketches.
7.2.1
Digital and analogue fabric switches
To sketch ideas for fabric interactions, it was crucial to understand how an electronic
interface works. Over the years, with the growth of technology and design one
sees many kinds of physical interface elements such as switches, knobs, sliders,
trip switches, press buttons, touch screens etc. But at a basic level, every physical
interaction generates either a digital on/off response or outputs a range of values that
can be interpreted by the electronic circuit in different ways. There are numerous
ways to achieve these results and some are better than others according to different
contexts and needs.
37
ag
ec
ha
ng
e
vol
t
INPUT (physical interaction)
vol
t
Figure 24. Physical interaction
interpreted by the microcontroller or electronic circuit in
the fabric interface as change in
voltage.
ag
ec
ha
ng
e
Thus, all interactions, physical gestures and actions that are designed have to ultimately
generate a measurable change in voltage to be read by a micro-controller (see Figure
24). It was realized while working with fabric triggers that they invariably include
electrical noise due to being analogue circuits. This noise can be compensated or
exaggerated as needed using software or other electronic components. A pure digital
switch that produces only two clear values was not possible to make. Rather, digital
switches in the case of knitted fabrics means those that generate a considerable
difference in voltage between the on and off states. A traditional analog switch like
a potentiometer in the case of knitted fabrics is one that generates determinable
voltage changes proportional to the nature or extent of an interaction. The resultant
change in voltage in both cases can then be translated to any programmable function.
microcontroller/
electronic circuit
OUTPUT (feedback)
Fabric interface
7.2.2
* Conductivity
* Shape
* Size
* Weight
* Hardness/ Softness
* Temperature
* Elasticity
* Moisture
Working with physical properties of other objects
The physical properties of common objects were identified to incorporate them as
essential elements for activating the fabric triggers. Working with physical properties
like weight, shape or size helped to generalize the requirements for making the soft
triggers work and made the incorporation of other objects more flexible and open to
interpretation. Figure 25 lists the various physical attributes that common domestic
objects possess.
Out of the many properties listed, only a few could be prototypes as fabric interfaces.
Since the knitted fabrics are soft and have some elasticity, stretching it is an intuitive
action. Putting things inside knitted forms to stretch it could be one way of using
external objects so that their properties like shape, size or weight could be ‘measured’
using stretch-sensitive conductive yarn. Conductivity being essential to the soft
circuit was an object property that could included in many trigger concepts. Whereas
Figure 25. Physical properties of temperature or moisture were more difficult to sense using only knitted fabrics.
common domestic objects
38
7.3. Generating ideas and concept sketches
The idea generation process faced the following questions :
1. How to adapt fabric qualities to create input triggers that responded to physical
properties of other objects such as weight or conductivity?
2. How to create a comprehensive mapping of the different states assumed by a soft
trigger?
3. How to approach the various existing scenarios and contexts that include fabrics,
for example a picnic in the park or inside a kitchen, to extract opportunities for
designing electronic interactions ?
While taking inspirations from the reference base and keeping in mind the nature
of electronics, the sketching process in the beginning was quite open and not
constrained by practical concerns. Sketching was an important tool to articulate and
think of ideas. I approached the subject from different directions as a strategy to
avoid getting stuck with similar ideas while trying to cover all of the questions raised
above. For instance using a fabric action as a starting point and using objects from
an actual domestic setting as a starting point to brainstorm ideas for soft triggers
were two different approaches that collectively led to concepts that had a wider range
of forms and interactions. In the following sub-sections I would cover the different
starting points or approaches taken for generating ideas for fabric triggers while also
dealing with the questions above.
7.3.1 Translating fabric related actions into triggers
In this approach, the primary focus was to identify opportunities for inserting circuitry
into existing fabric actions. Not much attention was paid to the use or the context from
where these actions were extracted except in some cases where it came naturally.
I started from the fabric interaction map (see Section 7.1) to sketch ways of
incorporating conductive thread and soft circuits in order to generate a readable
electronic impulse from the listed interactions. I also kept in mind the necessary use
of another object as a trigger element. It was always helpful to think of a few use cases
Figure 26. Using the action of
along with the concept to better visualize the fabric interface.
‘knotting’ as a trigger.
For example, ‘knotting’ is a fabric action. Knotting two pieces of conductive fabric
pieces could be used for making a connection (see Figure 26). Knotting, as an
interaction, could thus lend itself to be a fabric ‘digital’ on/off switch. To include
39
other objects in this trigger, one could design it in such a way that the pieces of fabric
have to be knotted to the same conductive object from its surroundings to connect
them.
Similarly, stretching of fabric could be detected by using a conductive yarn that
changes its resistance when pulled. A trigger that resembled a wrist band could be
made such that when stretched around different objects it generates different outputs
depending on the extent of stretch. This could be a way of making a soft trigger that
responds to the size or shape of the object (see Figure 27).
Not all the sketches proved to be workable. Prototyping was an integral part of this
process and a key factor in determining if the sketches that worked in theory would
actually work when implemented with the materials. This aspect is covered in detail
in section 7.5.
7.3.2
Figure 27. Concept sketch of
a stretchy band that responds
to different thicknesses of the
objects it is stretched around.
An important aspect to all approaches taken to create knitted triggers was to the
ability to identify and work with different “states” of a fabric object. A blanket is
folded when stored or spread when in use. A knot is tied or loose (see Figure 28).
A pocket is full or empty. Extracting these formal or gestural ‘situations’ of fabrics
indicating their state of ‘use’ and ‘non-use’ was a technique to relate them to, for
instance, the ‘on’ and ‘off’ states in traditional electronic devices. These associations
worked well as metaphors for indicating the different electronic outputs of a fabric
interface while creating a more comprehensive mapping of forms and gestures.
7.3.3
Figure 28. A pouch shaped soft
trigger concept that uses the
states ‘open’ and ‘close’ of a knot
as indicators.
40
Working with ‘states’ of fabric objects
Using scenarios and use-contexts as starting points
Finding places for fabric triggers to occur around objects in a real setting or scenario
was another approach taken to generate ideas. I believed involving objects from
one context in the design process might naturally lend itself to others as well. The
situational or perceptual maps were a useful reference in this case. For example,
taking ‘kitchen’ as a scenario, I was able to find objects that normally come in contact
with fabrics like a handle of a cupboard drawer from which a hand towel hangs or
the cutlery that is wiped with a cloth to dry. I also found other objects like a metal
faucet which could used for its conductivity or for its peculiar shape and movement
(see Figure 29).
Starting from a place helped in involving other objects from a context while incorporating
a scenario or a story that was understandable and thus also re-interpretable. A towel
shape usually hangs temporarily on a handle or a hook while in use. A fabric trigger
that is ‘activated’ when it is hung from a metal bar is indicative of this but can be
activated by hanging from any appropriate metallic object. Thus a design inspired
from one context could be generalized for multiple interpretations while involving
other objects having similar physical properties as a metal handle of an drawer.
Conductive parts
The fabric stretches in different directions
and makes corresponding shapes with the
turning of the faucet handle and hose.
When hung on the metal bar,
the two conductive parts get
connected.
7.3.4
Working with interaction methods
Different interfaces we interact with possess different yet understandable logic
systems. This is communicated in many cases through their formal affordances like
shape and degrees of freedom. A knob-shape, for example, can be turned. If its a
full rotational knob or one with end points determines the nature of the values it is
associated with. A knob is directional and linear in the sense that one has to follow
path to reach the point desired. Similarly in other interfaces, the path is not a factor
and one can jump directly to any needed place like in a keypad. Interacting with
fabrics also work with different ‘flows’ or steps in interactions. Tying a shoe lace or
buttoning a shirt follows a linear order where the same path is followed for doing a
task. Similarly, folding up a sleeve or using a zipper focus more on the direction of
the interaction. In other cases, the time taken or the duration of an interaction affects
Figure 29. Sketches (Left)
Using the metal handle of
kitchen drawer as an activator.
(Right) A soft trigger that
stretches in different directions
according to the movement of
the nozzle of the faucet.
41
* Direction
* Path
* Duration
* Only destination
* Combination
Figure 30. (Left) Example
sketch for an interface that
uses ‘Path’ : A soft trigger
containing four buttons and
a conductive string that needs
to be wound around them.
Depending on the path taken or
the pattern created between these
four buttons, different values are
triggered.
Figure 31. (Right) Example
for an interaction that uses
‘direction’ : A sketch for a scroll
type interaction with a fabric
trigger hanging on a metal rod.
Different values are generated
depending on the the direction
of pulling.
42
the feedback for example creating deep wrinkles on the couch cover as a result of
long hours of use. Some other interactions work with combinations. A simple example
of this would be the kind of knitted hats that have attached scarfs, depending on the
combinations used, these fabric artefacts could be hats, scarfs or both.
After recognizing these different flows or methods in interactions, I attempted to use
this as an approach for concept sketches while of course keeping the fabric actions
and reference base in mind. So taking one ‘method’ at a time, I tried to come up
with different fabric interfaces (see Figure 30 and Figure 31). This exercise was an
interesting and challenging one.
7.4.
Materials and tools
All the materials and tools used in the project were available in local shops or easily
ordered online from within Europe. The practical exploration focused on knitted
fabrics investigating it as a medium for creating soft triggers. Traditional construction
tools for knitting and sewing were used to incorporate conductive yarns and for making
other parts of the soft triggers. The electronics comprised of passive components such
as resistors, output devices like LEDs and in some cases a Lilypad, a sewable microcontroller, to experiment with more “features”.
The characteristics and choice of these materials and tools are further explained
below. Most of these aspects surfaces during prototyping. However, in the text, I
present them together before going further, as describing the materials and tools in
detail brings forward the constraints presented by them which defined the boundaries
of the prototyping process described in the next section.
1. Knitting yarns
Knitting yarns come in different colours and thicknesses. Although not all of
them are elastic in nature, the knitted structures provide elasticity to the fabric
thus creating soft and flexible forms. Fine to medium fine yarns were used to knit
the prototypes for this project. Regular yarns were knitted along with conductive
yarns to form soft circuitry. The different conductive yarns used are explained
below.
2. Conductive yarns
Conductive yarns are silver coated nylon yarns or made from steel fibres and
designed to behave and be used as normal yarn. The nature of the metal coating
enables these yarns to have different levels of conductance giving them different
properties. I have used five kinds of conductive yarns of different thicknesses
and conductive properties (see Figure 32). Table 1 shows the different conductive
yarns used and their resistance values.
Conductive thread
235/34 2 Ply HC Conductive Silver Thread
Bekinox steel fibre
Nm 50/2
Silver Plated Nylon 117/12 x 2ply Thread
234/34 4 Ply HC Conductive Silver Thread
Manufacturer
Shieldex Statex
Schoeller
Shieldex Statex
Shieldex Statex
Resistance/ 50cm (ohms)
40 approx.
17 approx.
11 approx.
Table 1: Details of the conductive yarns used.
23 approx.
43
Figure 32. (Right) The
different conductive yarns
used.
The silver coated Statex yarns were found to be much better for knitting as they
matched the thickness of the normal yarn, were stronger and unlike the steel fibre
yarn, they did not fray while knitting. The stretchy conductive thread worked
well with the smaller knitting machines. However, it was often found to break in
the industrial knitting machine if not combined with another normal fine yarn.
These conductive yarns were not stretchy by themselves but when knitted with
normal yarn they assumed the elasticity of the overall knitted structures.
3. Basic electronics
The fabric in the soft triggers itself acts a sensor or switch that activates or
responds to interaction. This was made possible by integrating conductive yarns
(explained above) and some small electronic components into the soft circuits
mainly to enable sufficient current flow. (see Figure 34)
Pull-up resistors were incorporated in some cases to get a measurable reading
from the soft trigger circuit. Button cell batteries and Lithium 3.3 V batteries
were used for power supply. These constituted all the electronics needed for
the working of the soft trigger. However, to give a visual or tactile feedback to
the user and to indicate the ‘state’ of the trigger either a sound buzzer, vibration
motor or LEDs were incorporated into the soft trigger as well. A Lilypad was also
used with a few designs of soft triggers to create slightly more complex feedback
loops. It also helped to increase accuracy by enabling noise reduction through
programming software.
Figure 33. Twisting the legs of
the LED with pliers to make it
easy to sew on fabric
The LilyPad Arduino (see Figure 34) is a microcontroller board designed for
wearables and e-textiles. It can be sewn to fabric and similarly mounted power
supplies, sensors and actuators with conductive thread. The LilyPad Arduino
was designed and developed by Leah Buechley and SparkFun Electronics.
(Buechley, 2009) The buzzer, vibration motor and some of the LEDs used were
part of LilypadArduino and thus were easily sewable on fabrics. The resistors
and regular LEDs had to be prepared by first twisting their legs into loops and
then sewing conductive yarn through to attach them (see Figure 33).
A multimeter was often an important requirement to check the connections and
for troubleshooting any electronic problems.
4. Traditional construction tools
The triggers were created and put together using traditional fabric construction
tools. A silver reed home knitting machine was used to knit the parts and that
44
235/34 2 Ply HC Conductive Silver Thread
Bekinox steel fibre
Nm 50/2 80% Polyurethane, 20% Inox steel fibreThread
Silver Plated Nylon 117/12 x 2ply Thread
234/34 4 Ply HC Conductive Silver Thread
45
Multimeter
Crocodile clips
USB LiPo charger
Polymer Lithium Ion Battery 110mAh
Lilypad power supply
Lilypad vibe-board
Lilypad buzzer
Lilypad Arduino
LilyPad FTDI basic breakout board
Mini USB cable
Light emiting diode (LED)
Button cells
46
were then stitched together by hand or with a sewing machine. Other fundamental
tools like a stitch remover, measuring tape, needle threader etc were also useful
(see Figure 35).
Using knitting as a technique was a decision made at an early stage in the
project. The knitting machine is a unique tool and has a versatile but well defined
language that needed to be studied in order to incorporate soft circuits. Like any
other tool, it presented vast possibilities but also had some strict constraints. A
few things to keep in mind when prototyping were that knitting only happens in
one direction and that there was a possibility of having the conductive yarn only
on one side of the knit depending the machine.
7.5.
Figure 34. (Left) Electronic
tools and components used.
Prototyping
Prototyping on the whole was an extremely iterative process. Every sketch to be
prototyped had to be first redrawn for the knitting machine. The soft circuit had to be
planned accordingly making sure that all the conductive yarns were well insulated
and that it would be secure to interact with. In most cases the trigger was knitted
in parts and then sewed together later while also adding other required electronic
components like resistors or LEDs.
In the below sub-sections I would give a detailed account of the prototyping process.
I would also highlight some key issues like insulation and power source needed for
the working of a trigger and illustrate different design solutions deployed to overcome
these.
7.5.1
Knitting-drawing and circuit-planning
A sketch that needed to be prototyped first had to be drawn as it would be constructed
with the knitting machine. In most cases this was determined by where the conductive
yarns would be knitted for the trigger to work properly. The size and scale of the trigger
were determined by doing sample knits. The drawing to be prototyped contained
dimensions of each piece in centimetres or with the number of rows and columns
to be knitted with the parts knitted with the conductive yarns clearly marked. (see
Figure 36)
The drawings also included a plan for how the soft components would be powered
and how the data cables from the triggers would be taken to the micro controller.
47
Felt
Yarn
Scissors
Textile glue
Measuring tape
Needle threader
Stitch remover
Thread
Pins
Pin cushion
Sewing needles
48
Insulation was a key concern and the main factor in designing the circuits. The
knitting drawing laid out a plan for the parts to be knitted and techniques to use
so that the data lines would not criss-cross and would follow the most efficient path
between the fabric sensors and the micro-controller or the power supply.
Figure 35. (Left) Traditional
fabric construction tools used.
Figure 36. An example of a
rough sketch and knitting
drawing containing the
dimensions of 2 sides of
the trigger to be knitted
separately.
7.5.2
Power supply
For this project I have used LEDs and other small output devices with maximum
requirement of 5V electricity. This was a decision made to be compatible with the
power output of lilypad arduino and to be able to use other light weight power options
available for the same voltage. In the analogue circuits a 3V button cell was sufficient
to light an indicative LED. Finding the commercially available plastic button cell
holders too bulky, I designed my own sewable button cell holders made from felt and
conductive yarn (see Figure 37). These were small, easy to stitch on and resembled
small embellishments or beads sown into fabrics (see Figure 38).
Figure 37. (Left) Button cell
holders made from felt.
Figure 38. (Right) Button cell
holders and LED sewed onto the
surface of a trigger.
49
I also tried using a 3.3V Lithium battery in some triggers, which I found were easy
to house discretely in small knitted pockets within the surface of the fabric. I used
circular knitted channels to also hold LEDs and other components in many cases (see
Figure 39). A detachable micro-controller (Lilypad) + power module (see Figure 40)
was also designed separately to be attached to a few triggers to generate more distinct
outputs. The description and design of this module is made more clear in the end of
the section.
Figure 39. (Left) Close up of a
Lilypad LED module descretely
inserted inside a circular-knitted
portion. (Centre) A zoomed out
view of the same knitted surface
when the LED is off. (Right) The
surface of the trigger when the
LED is on and shines through
the layer of fabric.
7.5.3
Stitching the knitted parts together
As mentioned before, to secure connections or to incorporate conductive yarns in
a required direction, often the triggers were knitted in parts. This was followed by
securing the loose hanging threads and cutting and glueing the ends to make sure
they would remain in place. It was especially important to glue all the loosely hanging
conductive yarn neatly so they do not create short circuits.
Figure 40. The Lilypad + power
module powered with a LiPo
110mAh battery.
Most of the triggers were designed in a way that the ‘sensor part’ was knitted separately
than the part carrying the soft cables. Thus the part with the hems or pockets, made
to carry soft wiring, needed to be inserted with conductive yarns and stitched on the
appropriate places to connect them to the sensor portions.
Once each of the pieces were prepared, they were stitched together either by hand
or with a sewing machine. Once stitched the connections were checked for proper
functioning which if did not work as intended was followed by troubleshooting. The
LEDs and other output devices were also stitched on wherever required. (see Figure
41)
7.5.4
Figure 41. (Right) Steps
involved in putting together a
knitted trigger.
50
Thinking about output indication for triggers
Designing outputs with respect to functions associated with a fabric interface was out
of the scope of this project. However, outputs as feedback of an interaction with the
designed fabric triggers were essential to indicate its state.
In some analog circuits LEDs were used to indicate the current flow and the inherent
noise. The LEDs would often flicker slightly and then be bright showing the inherent
glue
there were 2 same-sized discs and a long 2 with a needle and glue to 3 to get a neat look.
1 one,
knitted strip to be attached between.
secure them.
Knit the different parts of the trigger. For this
4 pins.
Attach the parts together roughly first with
6 Remove the pins afterwards.
Knit in the loose threads
Cut away the extra thread
5 appropriate places.
Stitch the parts together using yarn and a needle.
Insert the conductive yarns and other components in the
7 need to be connected to the microcontroller.
Sew in the metal snap-buttons at the end of data lines that
and ready - but
8 Stitched
9 Invert for right side out.
still inside out.
the microcontroller and test
10 Program
the trigger.
51
electrical noise. Although this was an accurate indication the noise and the change
in brightness of the LED was not always perceivable.
I continued to work with LEDs but also tried connecting them to a micro-controller
to generate more perceivable difference and in some cases to visualize the noise
present in the system. Light was a good feedback especially for fabric digital switches
that showed on/off states. It was also easily documented in the print format. Other
outputs I tried were a buzzer for sound output and a vibration motor for a more tactile
feedback.
7.5.5
Designing the micro-controller unit
After making purely analogue circuits, a need was felt to interpret signals through
a micro controller for better feedback systems that can magnify small changes in
voltage. A ‘Lilypad Arduino-unit’ was made such that the same unit could be used
to plug different triggers. Modularity being essential, this unit was quite basic in
its design. Soft data lines from the lilypad were attached to metal press buttons (see
Figure 42), and the lilypad and the power units were sewed onto a flat knitted fabric.
Although it was not done for all the prototypes, some of the later soft triggers were
designed to have all the soft data wires coming to the same side or portion of the
trigger to make it easier to be connected with the microcontroller. They were also
sewed metal snap buttons at the ends of the soft triggers to easily attach them to the
corresponding leg of the micro-controller.
Figure 42. Detail of the microcontroller unit: The lilypad main
board connected to metal snap
buttons.
52
7.5.6
Testing , troubleshooting and programming
The prototypes once made had to be finally tested to see if everything worked as
intended. The prototypes that worked without the micro-controller had to be tested
to see if all the connections were well insulated and if the interaction with the fabric
trigger produced the desired output. This meant first measuring the resistance changes
or checking the different connections with a multimeter followed by ‘activating’ the
trigger to see it working. The prototypes that worked with a micro-controller had to be
further tested with a computer. As each prototype had different inputs and outputs,
a different code was written and uploaded onto the lilypad micro-controller for each
of the fabric triggers. Values generated from the interactions were then observed and
accordingly programmed to generate the desirable output. For example, the readable
values generated from a stretching trigger ranged between 40 to 500. Hence the
output on the sound buzzer were mapped to correspond this specific range of values.
Often it was also necessary to reduce noise coming from the circuit by averaging
or omitting incorrect values in software to generate a more recognizable connection
between interaction and feedback. Once everything was working well, the trigger
could be disconnected from the computer and tested independently.
Figure 43. Testing the newly
constructed soft triggers with a
micro-controller and computer.
53
8. Results
1. Taking fabric as the main reference, various soft triggers were designed and
prototyped. These soft triggers were designed to loosely sense properties of other
objects such as their weight, shape, size and conductivity. The next section
illustrates the different soft triggers and components created.
2. The making of prototypes and parts were documented and shared on a project
process blog: www.defint.wordpress.com. This is in the public domain and can
be viewed and used freely.
8.1 Gallery
This section presents the main results of the production process along with photographs
and descriptions. It includes the various soft triggers designed, examples of usecases for activating the fabric triggers with other objects in a home scenario and an
explanation of how they work. A few prototypes were connected to a computer using
a Lilypad to visually interpret the values they output when activated. The gallery
also includes still frames showing these soft triggers controlling the programmed
illustrations on screen. A copy of the Arduino and Processing sketches used to
program the micro-controller and the corresponding screen illustrations respectively,
are included in Appendix B.
While prototyping the triggers, some soft components were also designed like soft
button cell holders or knitted cables that could be used with the soft triggers. The latter
part of this section also shows the various soft components created. A set of videos
showing the interaction and working of some of the soft triggers and components can
be found in the included DVD – Appendix C.
The production process consisted of various steps, each involved producing a lot of
visual material, for example collection of visual references and all the concept sketches.
The highly iterative prototyping process involved many trials and experiments. Often
54
it took many trials before getting the yarn tension or technique right to produce the
desired piece of knitted fabric. Although these were also considered as results of
the production process, the gallery only includes the more finished versions of the
concepts and experiments of soft triggers and components. I intend to document and
give an overview of the secondary results including most of the visual materials like
sketches and other trials or steps involved in knitting the soft triggers online in the
project blog – www.defint.wordpress.com.
Page no.
Index of the soft triggers and components presented in the section.
56
58
60
62
64
66
68
69
70
71
72
72
73
73
73
74
55
A soft trigger that has four knitted ‘legs’. Otherwise appearing like a knitted belt or
scarf, this soft trigger is activated when two or more appropriate legs are tied to the
same conductive object. The additional ‘extension’ leg enables the trigger to work
over larger objects or connect different objects.
Conductive portion
in each ‘leg’
of the trigger.
Hem on either
side protects the
conductive region
from unintentional
contacts.
A hem fold-like stitch
carries the soft wiring
from the conductive
portion of the leg to the
central unit.
The soft wires from
each leg of the trigger
is sewed onto a metal
snap button to which
the output RGB led
unit can be attached.
The extension leg that can be
used with the knotting trigger
The RGB LED acts as the output by
changing its colour corresponding
to the three different knotting
combinations possible with the
trigger.
Initial concept sketch
56
Primary fabric action or properties used: Knotting
Property of other objects incorporated: Conductivity
Examples of how other objects can be used to activate the trigger around the house. This soft trigger could be activated by
knotting one or more conductive objects together. Objects used in the above illustrated cases without using the extension leg are:
an armchair, a kitchen utensil and towel warmer. The objects illustrated above used with the extension leg are an armchair and
cupboard door handles.
How it works:
Three legs of the soft trigger are connected to the three color outputs of
the RGB LED and the fourth leg is connected to the positive end of the
battery. Connecting one of the colour legs to the positive leg results in the
corresponding LED to light up.
3V
57
A soft trigger that resembles the sleeve of a shirt. The trigger is activated when the
cuff is connected to the inside layer of the sleeve. This can be achieved by piercing
through with a conductive object while folding up the sleeve. Different outputs are
produced according to the number of folds made in the sleeve.
Metal snap buttons at
the end of the sleeve
for connecting it to a
micro-controller
Blue conductive line on the
sleeve that can be connected
to the cuff with a sharp
conductive object like a
safety pin
Cuff knitted with
conductive yarn.
The cuff of the sleeve can be
folded up once or multiple times
and connected to blue line on the
sleeve with a sharp conductive
object like a safety pin.
Initial concept sketch
58
Primary fabric action or properties used: Folding
Property of other objects incorporated: Conductivity + sharpness
Examples of how other objects can be used to activate the trigger around the house. This sleeve shaped trigger could be put around
an object or kept separately. Objects used in the above illustrated cases are: a safety pin, sewing pin and a badge.
Visualization of the different states of the soft trigger by connecting it to a computer with a Lilypad micro-controller. As the sleeve
is rolled up and connected with a safety pin, the blue bar in the sleeve illustration on the screen gets correspondingly shorter.
How it works:
The blue knitted line on the sleeve acts a variable resistor. The cuff is
connected to the voltage line. The resistance changes with the point of
contact of the cuff and the blue knitted line, reducing as the cuff is folded
up closer to the other end. A sharp object is necessary to pierce through the
layers making a good contact between the cuff and the appropriate point on
the blue resistive line.
2.7 K Ω
Ain
+5 V
59
A woolly-cap soft trigger that is activated when hung from a hook or a metallic
object.
Loops on top of the
cap knitted with
conductive yarn in
the centre.
Hem structures of the
surface of the cap securely
carry the soft wiring.
Close up showing the button
cell battery discretely inserted
within the surface of the knitted
cap.
The woolly cap is made of 2
knitted halves stitched together.
A LED in the bottom of the cap
switches on when the 2 loops are
touching while hanging from a
hook or a conductive object.
Initial concept sketch
60
Primary fabric action or properties used: Hanging
Property of other objects incorporated: Conductivity
Examples of how other objects can be used to activate the trigger around the house. This soft trigger could be hung from different
places in a home. Although originally designed to work with conductive objects, the soft trigger also worked when hung with
the two loops touching. Hanging made the contact tighter due to its own weight. Objects used in the above illustrated cases are:
handle of kitchen cabinet, a coat hanger and a metal window knob.
The woolly cap soft trigger when worn.
How it works:
The two loops on top of the woolly cap act as a switch between the
circuit with the LED and a button cell battery. Thus hanging the cap so
that the loops are connected completes the circuit and lights the LED
at the bottom.
3V
61
A cushion-like soft trigger that uses conductivity of other objects to work. It has
two faces that can be activated simultaneously or separately giving the soft trigger
three possible combinations of active states.
Conductive yarn
knitted on the face of
the soft trigger.
Metal snap buttons
stitched at the end
of the soft data
lines for connecting
it to a microcontroller
The soft wiring
and LED module
inserted within
the surface of the
trigger.
This palm sized soft trigger is filled
with thermocole balls sealed inside
with a zipper stitched on the side.
Along with a LED module in the
knitted surface, a small vibration
motor is also connected which is
inserted into the cushion through the
end of the zipper.
Initial concept sketch
62
Primary fabric action or properties used: Softness
Property of other objects incorporated: Conductivity
Examples of how other objects can be used to activate the trigger around the house. This cushion-like soft trigger could be
activated by placing it over conductive objects or vice versa. Activating the green side resulted in the LED lighting up. Activating
the blue side switched on a small vibration motor giving a tactile feedback. Objects used in the above illustrated cases are:
Bottom of a moka pot, a utensil lid, kitchen sink, cutlery drawer and a mini swiss knife.
Visualization of the different states of the soft trigger by connecting it to a computer with a Lilypad micro-controller. The
illustration on the screen responds by colouring the side corresponding to the face of the soft trigger that is activated. Both sides
of the illustration are coloured when the two faces of the soft trigger are activated simultaneously.
How it works:
The two conductive wedge shapes on each face of the soft trigger are connected
when they come in contact with a conductive object. This completes the circuit
triggering the corresponding output from the micro-controller. The green side
triggers the LED and the blue side starts the vibration motor. The softness of the
cushion enables it to take the form of the object it is in contact with thus making
a better connection. The two faces in this case act as digital sensors and are read
by the digital input pins on the Lilypad.
VIBR
MOTR
D1OUT
D1IN
D2IN
D2OUT
63
A stretchy cylindrical soft trigger that detects the approximate shape of other
objects. This knitted tube can be stretched around different shaped objects to
generate different results.
Metal snap buttons
stitched at the end
of the soft data lines
for connecting it to
a micro-controller
Small LED modules
inserted within the
knitted surface in the
white bands.
The other side
has three lines of
stretch-sensitive
conductive yarn.
This soft trigger is made of two parts. On
side has the stretch-sensitive conductive
thread which acts as the sensor and
other side has three corresponding
output LEDs. The soft data lines are
carried inside hem structures on the side
edges of the soft trigger.
Initial concept sketch
64
Primary fabric action or properties used: Stretching
Property of other objects incorporated: Shape
Examples of how other objects can be used to activate the trigger around the house. Apart from different shapes, the objects also
needed to be larger than the knitted tube to activate it. Objects used in the above illustrated cases are: a book, a reading lamp
and a cushion.
Visualization of the different states of the soft trigger by connecting it to a computer with a Lilypad micro-controller. The two
white lines on the screen represent the contour of the stretchy soft trigger. The contour lines bend according to the shape of the
object the soft trigger is stretched around. The portion of the soft trigger that is stretched over a certain point results in the LED
in that region to light up. The three stretched regions are represented by a blue, yellow and green LED respectively.
How it works:
The soft trigger has three rows of stretch sensitive conductive yarn
knitted along the width of the tube that divides it into three horizontal
regions. The stretch sensitive conductive yarn changes resistance
when stretched and is measured by the micro-controller. When the
soft trigger is stretched over an object, the three conductive yarns give
three different resistance values according to the amount of stretch.
This can be loosely equated to the approximate shape of the object the
soft trigger covers.
D1OUT
D2OUT
D3OUT
+5
A1IN
A2IN
A3IN
2.7 K Ω
65
A scroll-like fabric trigger that can be activated by hanging it over a metal bar. The
soft trigger can be pulled down or up like a scroll around the metal bar activating a
different region of the knitted scroll depending on the portion in contact with the
bar.
A soft button cell holder
and a LED connected to
the conductive strips on
either side.
Gaps in conductive
yarn indicating the
different regions that
can be activated.
The soft trigger has two
conductive strips on each edge.
The length of this knitted scroll
is divided into three regions that
can be activated by hanging and
‘scrolling’ the trigger around a
metal bar. There are three LEDs
corresponding to each region that
light up when activated.
Initial concept sketch
66
Primary fabric action or properties used: Hanging
Property of other objects incorporated: Conductivity
Examples of how other objects can be used to activate the trigger around the house. Due to the light weight of the soft trigger,
more objects were required to hold the trigger in place on the metal bar. In this case a clothes peg and a hair clip did the job.
Conductive objects used in the above illustrated cases are: a hanger in the cupboard and a towel warmer in the bathroom.
How it works:
The conductive strips on the edge of the soft triggers are connected to a simple soft
circuit with a LED and a battery. Hanging the soft trigger over a metal bar completes
the circuit resulting in the LED to light up. The length of the trigger is divided into
three regions. Thus by ‘scrolling’ the trigger in any direction, the colour of the LED
can be controlled according to the region which is in contact with the metal bar.
3V
3V
3V
67
A version of the cushion-like soft trigger that can be activated using conductive
objects.
Primary fabric action or properties used: Softness
Property of other objects incorporated: Conductivity
The soft trigger has two conductive
strips on each edge. A detachable
LED module with an integrated
battery is fixed on using metal
snap buttons. When placed over
a conductive object, the circuit
is completed causing the LED to
light up. The cushion shape is filled
with waste yarn. The mouth of the
cushion is currently open to keep
an option of filling it with another
material or using it for temporary
storage with or without the LED
module attached.
Examples of how other objects can be used to activate the trigger around the house. The small cushion could be placed over or
wrapped around conductive objects. The objects used in the above illustrated cases are: a candle stand, a room door handle and
a cupboard door handle.
68
A soft trigger that responds to the conductivity and size of the object kept inside
it’s pocket.
Primary fabric action or properties used: Stretching
Property of other objects incorporated: Size + conductivity
The soft trigger is knitted
with two rows of low
resistance conductive
yarn and a row of stretch
sensitive conductive yarn
in the middle.
This pocked shaped soft trigger can be
activated with both conductive objects
and with objects of appropriate width/
size. The two knitted rows of low
resistance conductive yarn act as a
switch that activates when a conductive
object comes in contact with both the
rows. The stretch sensitive conductive
yarn on the other hand responds to
the size of the object in the pocket. A
wide enough object stretches the pocket
making the resistance across the two
ends of the stretch sensitive yarn to
drop, thus lighting the LED.
Examples of how other objects can be used to activate the trigger around the house. The objects used for their size in the above
illustrated cases are: a thermos cap and a glass bottle. Objects used for their conductive properties are a couple of spoons and
a wrist watch.
69
A soft trigger with conductive furry textures that when connected with conductive
objects, activates the trigger.
Primary fabric action or properties used: Softness/ Texture
Property of other objects incorporated: Conductivity
The soft trigger is made of four
conductive pompoms squeezed
between the layered surface of the
knitted fabric giving the trigger a
unique texture and tactile feel. The
pompoms are connected to LEDs and
batteries, also inserted within the
knitted fabric. Placing a conductive
object on the pompoms completes
the circuit lighting the connected
LED. There are two LEDs that can
be triggered by connecting 2 or more
pompoms in different combinations.
Example of how other objects can be used to activate the trigger around the house. The object used in the above illustrated case
is a pair of scissors.
70
A soft trigger that can be activated by crumpling it. Stuffing the knitted trigger in an
appropriate sized object helps to maintain it’s crumpled state.
Primary fabric action or properties used: Crumpling
Property of other objects incorporated: Volume
This soft trigger is a single piece
of knitted fabric. It consists of a
few knitted rows of high resistance
conductive yarn which is connected
to a LED module forming a complete
circuit. Crumpling the knitted
trigger reduces the resistance across
the two edges of the knit allowing
enough current to pass through the
soft circuit thus lighting the LED.
Initially tested with crocodile clips, I
later stitched on metal snap buttons
on either end of the knitted trigger
to be able to connect it easily to a
LED module.
Examples of how other objects can be used to activate the trigger around the house. Crumpling the trigger activated it. However,
objects of small enough volume were needed so that the soft trigger can be stuffed tightly inside to maintain it’s crumpled state.
The objects used in the above illustrated cases are: a film canister and an i-sight webcam stand.
71
Soft components or modules designed for use with the knitted triggers:
Soft Button-cell Holders
Soft button-cell holders made
with felt and conductive thread.
They are small in size and easy
to sew on or insert between layers
of knitted fabric. Compared to the
commercially available plastic
button cell holders, my soft version
was more ‘fabricy’ and good for
integrating into soft circuits and
ideal for lighting a LED. They
were made to house a 3V button
cell battery. It is also possible to
have 2 batteries stacked inside for
a 6V output.
RGB LED Module
A circular detachable RGB LED
module that assists in visually
representing the state of the fabric
triggers it is connected to. The four
legs of the RGB LED are connected
to snap buttons at the border of
the circular form, thus making
it possible to attach it to other
components or triggers. This knitted
module also has a 3V battery in a
soft cell holder that is attached to
the LED on the reverse side.
72
Knitted Cables
The knitted cables are narrow
tubes that have conductive yarn
threaded inside them. This provides
a well insulated means to make
soft circuitry. The conductive yarn
is stitched to metal snap buttons on
either end which make them easy to
connect with other components or
cables. Each end of the knitted cable
has both sides of the snap buttons
for convenience. This also allows
for multiple cables to be stacked
creating a junction point or parallel
connections in a circuit. These knitted
cables were mostly used to connect
the soft trigger prototypes and other
components with the Lilypad microcontroller.
Knitted Resistor Cables
These short and brown coloured
knitted tubes are similar to the
normal knitted cables except that
they have a 2.7 K Ω resistor sewn
inside. They were used mainly as
pull-down resistors for reading
analog soft trigger values.
Soft Component-mount
The soft component mount is a
small piece of knitted fabric onto
which components like a Lilypad
vibration motor is stitched on and
connected to metal snap buttons.
These components were mostly used
as output and the mounts made it
easy to attach and detach them from
the soft triggers.
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Lilypad + Power Module
The Lilypad + power module
is a band of knitted fabric
with circular knitted channels
that run parallel along the
length of the fabric. These
channels allow conductive
yarn to be threaded inside
them for securely connecting
the different pins of the microcontroller to the corresponding
metal snap buttons. For this
project, I have used in total 6
pins of the Lilypad – 3 analog
and 3 digital pins. The Lilypad
power module is also stitched
on and connected to the
Lilypad with conductive yarn
running through the narrow
channels in the surface of the
knitted fabric. The FTDI board
on the Lilypad allows it to be
connected to a computer with
a USB cable. Alternatively,
connecting a battery to the
power module can also be used
as more portable source of
power. The metal snap buttons,
one for each pin and two for
power and ground respectively,
are marked with different
coloured threads to easily
distinguish between them. The
colour markers are also useful
to mark the appropriate snap
buttons on the soft triggers with
the colour of the pin to which
they would be attached.
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9. Summary of insights from the production process
1. Knitting machine as a construction tool
Time and skill: Knitting enabled construction of custom-circuits on the fabric.
The rich resources of knitting techniques and patterns presented different
possibilities to be adapted advantageously for e-textiles, like knitting rib
structures where stretchiness of the fabric was important for the trigger. Working
with the knitting machine was a slow process. It often required a couple attempts
to get the knitting right (see Figure 48). An understanding of using the right
yarns, tensions, weights and most importantly troubleshooting when something
went wrong were skills that developed slowly with practice over the period of the
project.
Figure 44. Knitting machine
Using an industrial knitting machine: At a later stage in the project an industrial
knitting machine was used with to prototype a few triggers. The programming and
the use of the industrial machine, although done by an expert, was complex and
time consuming. It was found to be inefficient for small constructions especially
those using thinner conductive yarns. However, it enabled speedy prototyping
and gave a ‘professional’ finish to the triggers.
2. Interpreting different knitting techniques for e-textile construction:
Different knitting techniques were found to have unique properties that were
useful for integrating electronics or soft circuitry in different ways. Some
examples are listed below:
Ribs for stretchiness: Knitting ribs resulted in elastic structures that were useful
to make triggers that responded to stretch (see Figure 45).
Inlay for texture: Inlay knitting with the combination of thick and thin yarns
could be used to create tactile textures. However, in this technique the floating
conductive yarn needed to be cut by hand wherever required and the ends glued
to keep in place, making it impractical.
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Circular knit for pockets within the fabric layer: Circular knitting in combination
with regular knitting proved to be a very useful technique as it allowed for small
pockets to be inserted between the layers of the surface. This was a discrete and
elegant solution to incorporate small electronic components and soft wiring into
the triggers (see Figure 46).
Figure 45. (Left) Knitted rib
structure.
Figure 46. (Centre) Close up
of a small pocket knitted using
circular knitting to house battery
and led.
Two yarns for double sided knitting: With double yarn single knitting, two different
yarns could be knitted with each showing only on one side of the knitted fabric.
This was a good technique to use when conductive yarn was needed to be kept
only on one side of the fabric substrate.
Figure 47. (Right) A RGB LED
module made with circular
knitting.
Disc knitting for component mounts: Disc knitting was another important
technique that resulted in radial conductive lines coming from the centre of the
disc. This was different from the normal horizontal knitting that only produced
parallel conductive lines. Thus, disc knitting was useful to incorporate small
electronic components with multiple legs, like a RGB LED (see Figure 47) or a
logic gate, to be placed in the centre of the disc and connected easily to the rest
of the soft circuit.
3. About the properties of conductive yarns and threads used:
The workability of the prototypes was largely dependent on the different
conductive yarns I was working with. Their incorporation in the soft circuitry
were guided by their different properties. The insights regarding the quality of
conductive yarns and their roles were as follows:
Figure 48. Various attempts
at knitting a disc shape before
getting it as intended.
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Using high resistance yarns: Higher resistance threads were better for making
potentiometers.
Using stretch-sensitive threads: The thread that changed its resistance according
to stretch was very usable in the context of knitted fabrics as they inherently
have elasticity due to the knitted structures. This stretch-sensitive conductive
thread (Shieldex Nm50/2) was found to work best for a width of around 50 rows
when incorporated directly in the circuit without a micro-controller interpreting
its values. Making the stretch-sensor too long required the fabric to be stretched
to an unnatural extent in order to produce a significant change in current flow. On
the other hand shorter lengths let too much current pass even when not stretched.
Using medium and low resistance yarns: The low resistance yarns were ideal
for making power connections. The thin conductive yarn from Sparkfun has
medium resistance and was ideal for shorter length power connections. Being
much thinner, it hid better between the layers of the knitted fabric. The Sheildex
yarns were easier to knit with than the Bekinox steel fibre yarns as the Sheildex
ones were better twisted and did not fray or break easily while knitting with the
thin needles of the machine. The Bekinox thread often broke and stretched when
knitted.
The conductive threads and yarns on the whole were found to be strong and longlasting. When stitched well, the connections were reliable and did not wear out
with use.
4. Solutions for insulation:
With fabrics, insulation often becomes a crucial concern. Fabrics by nature
are soft and stretchy. Conductive parts in the fabric need proper insulation in
order to avoid short circuits and other malfunctions. One needed to find ways
within the design to securely take the data lines to the desired output and power
supply without touching each other. Through my various experiments I found the
following ways to insulate soft wiring:
Figure 49. An example of a
knitted cable. It has metal snap
button at its ends acting as
connectors. The conductive yarn
runs inside the knitted tube.
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Layering: When more than one line of conductive yarn needed to be alongside
one another, they could be put on different layers to avoid any contact. Using
single knits was most appropriate as they could be layered without increasing
the thickness of the surface. While this might work in some cases, it could easily
become bulky if too many layers were needed.
Cables: Making narrow knitted cables to house the conductive yarn was a way to
cross over other conductive areas by safely taking the signal to the appropriate
‘port’. This could be designed as an aesthetic element or hidden inside the
surface of the knitted trigger when possible (see Figure 49).
Hem structures: Small hems could be knitted in the fabric to form rows that carry
the soft wiring. Conductive yarns could be strung through the hem securely. This
was however a tedious and slow process. A similar result can be achieved by
knitting a plain piece of fabric and then folding and stitching it into narrow rows
(see Figure 50).
Circular knitting: Rows of circular knitting when inserted in between rows of
double knit, formed narrow tubes in the fabric through which conductive yarn
could be inserted. This was a good way to seamlessly integrate soft data lines and
other components. However, if the circular knitting is too loose, the conductive
yarn inside may be at risk of getting exposed when the material is stretched (see
Figure 51).
Figure 50. (Left) Hem
structures: folded rows of fabric
to carry soft wiring.
Figure 51. (Right) Parallel
rows of circular knitting with
conductive yarn inserted.
5. Power sources
Power supplies are usually weighty, hard and require space. They are the most
“un-fabricy” things that need to be carefully integrated into the triggers without
making it too stiff. Thus power sources need to be accounted for early in the
design process to ensure a reliable design.
Button cells: Soft button cell holders were ideal for fabric triggers that worked
without the Lilypad unit. They were aesthetically easier to integrate with the
knitted artefacts. Usually connected to a LED, a sewed button cell worked for a
very long time. The battery could be replaced by removing the stitches along its
sides and re-stitching with a new battery.
LiPo batteries: While using the micro-controller unit, the power of 3.3 V Lithium
battery was sufficient to run the micro-controller and an output device. Being
rechargeable and of small size made these batteries were very convenient and
efficient.
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Figure 52. Circuit design
spanning over the entire fabric
surface of the cushion-like soft
trigger.
6. Designing the soft circuit
Circuit planning that was efficient and reliable for the soft triggers was also a skill
that developed over time and by learning from various mistakes made, for example
basic miscalculations in size or proportions or crossing data lines.
A regular PCB design requires all components to be laid out on its surface and the
connections drawn between them with no overlaps. Circuit designing for e-textiles
is a bit different. While the requirements of no overlap and efficiency are the same,
the circuit needs to be laid out over the three dimensional form of the soft trigger
rather than on a flat surface of a regular PCB (see Figure 52). The circuit design
was thus paralleled by a concern for using apt knitting techniques and tools. In other
words, the circuit design for an e-textile artefact is not a separate entity that can be
designed in isolation but is integral to the size, shape and feel of the entire artefact.
7. Making in parts
The circuit design often demanded that the soft trigger be made in parts to incorporate
conductive yarns in different directions or for insulation. Besides the necessity of
doing so for reliability, this method was also an efficient way of working as iterations
could be made to singular parts without having to re-knit the entire artefact.
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The first version of the cushion-like
prototype. Conductive strips on either side
with a detachable led module.
Several attempts at knitting a single
piece integrating the cushion part and the
output led. Trying to knit in the Bekinox
conductive yarn often resulted in breakage
of the knitted portion.
Figure 53. Iterative nature of
the prototyping process: Showing
the different design stages of the
cushion-like soft trigger.
After many trials, changing to a thicker yarn and loosening the yarn tension helped
to complete this cushion prototype. However, connecting the two parallel conductive
strips was inefficient and the green peas filling was just not working!
The discovery of using circular knitting for making channels and the inefficiency of the
cushion designs so far led to making this new version with a cylindrical shape and a neater,
more efficient circuit design. (Filled with thermocole balls.)
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10. Reflection
10.1. Looking at key factors that affected the design and attributes
of the knitted soft triggers
Flexibility of working with conductive threads to make soft sensors:
Conductive yarns were an important invention in the field as they made it possible to
create soft wiring and enabled the translation of electronic circuitry into that which
is appropriate for the medium of fabrics. As most traditional sensors act essentially
as potentiometers of different kinds, it was possible to make some by using only
conductive threads and yarns of varying resistance while keeping the electronics at a
basic level. There were mainly three kinds of soft sensors used in the triggers:
One was the stretch sensor made by knitting high resistance conductive yarn into
the knitted fabric t­hat changed it’s resistance according to the extent the fabric was
pulled. The second kind was a ‘conductivity switch’ that was made by knitting an open
circuit with two conductive portions that when connected with an external conductive
object completed the circuit, thus activating the trigger. The third kind of sensor used
was a ‘string’ potentiometer that changed the current passing through it depending on
the amount of its high resistive surface that was in contact with the rest of the circuit.
These underlying three sensors were used to create the various triggers of different
forms and interactions. Some fabric triggers resembled other fabric objects, for
example the woollen cap shaped fabric trigger (see page 60) that is ‘activated’ by
hanging it from a hook when not in use or a pocket that can sense the presence of
objects inside it (see page 69). Other triggers were based on an action or gesture
related to fabric like stretching or pulling but were more abstract in form, for example
the tying interface with knitted ‘tentacles’ (see page 56) or the tube interface that
sensed shape of the object that it is stretched around (see page 65). Looking at
the these different results showed that many distinct designs and interactions could
be created with the same underlying electronics. In other words, even simple soft
circuits when designed specifically for the medium of fabrics could create new forms
and experiences through interaction.
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Opportunities gained from constraints of the traditional construction tools and
techniques:
Producing ideas that did not deviate from the central focus of looking and feeling
like traditional knitted fabrics was an important factor in designing the soft triggers.
The traditional construction tools also played a crucial role in this as they provided
the designs with practical constraints that were the same as those for the traditional
fabrics. This led to finding new ways of constructing circuits that are not usually
associated with electronics.
For example the directionality of the knitting machine forced the trigger concepts to
be reworked by breaking them up into parts to assure the working of the soft circuitry.
Instead of thinking about a flat circuit layout, the trigger designs needed to be broken
down into knitted parts containing portions of the circuit that would later come
together as a trigger. This often affected the form and shape of the triggers. On the
other hand, fabric construction techniques needed to be reinterpreted for electronic
purposes. ‘Re-using’ known fabric forms and aesthetics assured that the artefact
would emit more fabric-like qualities than that associated with electronic interfaces.
For example ‘hem stitching’ is a sewing technique involving folding up the edge of a
fabric and stitching it to avoid fraying and securing loose thread ends. This results in
a hollow fold at the edge of the fabric which in the context of e-textiles was ‘re-used’
for insulating soft wiring. Thus working with traditional tools and techniques led to
soft trigger designs that were inspired by fabrics as material and also by aesthetic and
formal elements.
Working with these tools and techniques also meant trying out different things and
experimenting with different forms to find the most efficient and interesting solution.
The iterative nature of the production process became apparent in many cases when
one looked at the different prototypes made for the same concept or idea. In many
cases, the forms were influenced directly from technical requirements presented both
by electronics and the construction tools. For example, the soft cushion interface
developed from a normal cushion with two conductive parts to a cylindrical shaped
soft object that efficiently incorporated soft wiring to the micro-controller and
introduced more possibilities for interaction (see Figure 53).
Imagining use-cases from places and near by objects for trigger concepts:
The dimensions and proportions of the soft triggers were not planned but rather
loosely born from considering the objects they could interact with and the efficiency
of making them. However, the size and shape of these soft triggers were often affected
by how I imagined using the triggers. For example in the case of the knitted pocket,
I felt that giving a tighter, constraining size provoked more trial and experimentation
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leading to innovative interpretations than a bigger pocket that fits a large number of
objects. Another example of how projecting possible use-cases affected the design
was with the knotting soft trigger. When I found conductive objects disconnected
from one another but in close proximity – like small door handles on rows of kitchen
cabinets – I felt that expanding the capability of the knotting soft trigger to be tied
over longer distances and connect different objects would make it more interesting.
Hence I later knitted a long ‘extension leg’ that could be used to connect two separate
metal objects or tied to the knitted legs, hoping to expand the reach of the soft trigger.
Thus, the concepts for soft triggers were influenced by objects and scenarios that
were in close proximity to me and how I saw them as ‘useful’ for activating a trigger.
Some features or forms got added on or changed accordingly to accommodate more
diverse interpretations. Although I had some ideas for use-cases for these triggers,
actually interacting with them and giving them out to others brought along another
set of valuable insights.
10.2. Observations from a preliminary analysis of the soft trigger
prototypes
The prototypes once made were placed back in the home environment from where
the design concepts originally emerged. Since the soft triggers were designed to work
with multiple objects, I tried to use different objects around the house to try and
activate them. I also gave a couple prototypes to my colleagues to see their initial
reactions. This was a way to study the prototypes by reflecting on the experience of
interacting with them and other objects in their surroundings.
10.2.1 Insights from finding different ways to activate the soft triggers in a home
scenario
While conceptualizing designs, I had some ideas regarding the different objects and
scenarios where the triggers could be activated. However, the actual task of finding
objects that worked with the triggers was a totally different and interesting experience
than the one anticipated. The soft triggers reacted to physical properties like volume,
shape and conductivity, and thus could be activated by finding an object from their
environments that embodied the appropriate physical attributes. In a home setting,
each trigger could be activated in multiple scenarios and using different things, thus
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highlighting their flexibility across different use-cases. For example, the knitted legs
could be activated in a kitchen scenario by tying the required combination of legs on
a metal handle bar of a cupboard or knotted around the metal legs of a chair in the
study. The different scenarios and objects that the triggers were placed in can be found
in chapter 8.
Described below are the key insights from my experience of interacting with the soft
trigger prototypes:
Revealing unexpected properties of common objects: In many cases, unexpected
properties of common objects emerged while trying to get the trigger activated. For
example, trying triggers that required to interact with conductive objects resulted
in presuming all metallic looking objects, like door handles or chair legs, to be also
conductive. This was often proved wrong when triggers did not work, thus bringing out
qualities in objects different from those expected.
Intuitive analysis and comparison of near-by objects: In most cases, interacting with
the knitted soft triggers and other relevant objects resulted in constantly comparing
different objects with one another to assess how well they worked with the fabric
trigger, thus creating an intuitive analysis of objects around, naming one to be better
than other. This specially became apparent while interacting with the sleeve-shaped
knitted trigger which worked with a relatively narrower set of objects. The sleeve
trigger required to be folded up and pierced with a sharp conductive object in order to
connect the different layers of fabric together. Sharpness being a key factor, the narrow
range of common household items to be used were safety pins, badges, sewing needles,
pins etc. Amongst these, the safety pin stood out as the most easy and convenient to use
as there were no sharp ends sticking out and the pin could be locked in place unlike
needles or pins. Thus a safety pin, originally designed to be used with traditional fabric
materials, was actually the most efficient to use with this soft trigger. Using a badge
was similar but a bit more tedious. The soft trigger prototypes, in this way, provided
multiple options for its activation and the user could find one or various preferred ways.
Object locations and emerging patterns: While finding different ways to activate the soft
trigger prototypes, I tried to utilize the entire home area for finding different objects
in typical home environments like kitchen, living room or bathroom. When all the
pictures taken with the working triggers were later observed, some simple patterns
began to emerge, such as triggers requiring conductive objects to work were primarily
placed in the kitchen or in the bathroom indicating the strong presence of such objects
in these areas of a home. However, the tube trigger which responded to the shape of an
object worked in a larger space of a home such as with a utensil in the kitchen, pillow
in the bedroom or a chair in the study.
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Unexpected interactions and new “problems”: There were also discrepancies between
the originally anticipated interactions and the practical ones. For example the scroll
shaped trigger (see page 66) was designed to be used over a metal rod-shaped
object and pulled up or down around the rod to generate different outputs. Although
the prototype worked well electronically, physically it was too light-weight to sit
firmly on the metal rod thus a reliable connection could not be made as intended.
This resulted in using other additional objects like cloth pegs or hair clips to hold
the fabric trigger in place. Thus the trigger encouraged further improvisation and
incorporated more objects than was originally intended.
10.2.2 Observations from giving the prototypes out to others
Along with trying to test the prototypes with different objects, I also gave a couple
prototypes to some of my friends to see their initial reactions and have an informal
feedback session. There were mainly two test users – Liisa and Lauri. A fabric trigger
prototype was given to each of them to keep and interact with for a few days along
with a scribble pad with a few directing questions to help them note down their
observations and suggestions. Taking pictures of their interactions with triggers and
other objects was also essential for documentation (see Figure 54 and Figure 55). The
prototypes were then collected back while I asked them a few more questions about
their general experience and their scribble pad- notes.
The idea behind this activity was not to conduct an in-depth user study but to
loosely observe the reactions and interpretations of others. I was also curious to see
these fabric artefacts in other people’s hands and how they hold or handle it. I was
especially inspired by the Placebo project by Dunne and Raby (2002) and the nature
of the interview questions they use for collecting insights from users about their
experiences of living with the critical design artefacts made by Dunne and Raby.
I followed a similar line of questioning which allowed for general feedback about
the look and feel and experiences with the artefact rather than focusing on specific
‘features’ or technical aspects. My motives behind the questions were to find out how
the users described or familiarized with the fabric artefact and related it to other
objects they know. I was curious to see how they would understand the working of
the fabric trigger and of course to see how they interpreted the fabric artefact in their
home environments.
The two ‘users’ Liisa and Lauri, both had very different experiences with their fabric
trigger. Below, I give a short description of each of their encounters followed by my
reflections. A copy of their scribble pads can be found in appendix A.
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1. Liisa
The fabric trigger given to Liisa was a pocket or a small bag-shaped object that had
three LEDs that lit up when the appropriate part of the fabric object was stretched
to a certain point. She was not told how the trigger worked as I wanted to see if
she would be able to understand the trigger without any outside help. The knitted
trigger was with her for 5 days during which she tried different interactions and
objects to experiment and understand the knitted pocket trigger.
Reading the notes from her scribble pad and talking with her revealed that it
wasn’t clear to Liisa how the trigger worked. Due to her prior knowledge of my
previous prototypes, she tried working with conductive objects but felt that most
of them were too heavy for the knitted pocket. Although she managed to switch on
the LEDs with a few methods, she was not able to deduce a clear reasoning behind
what the trigger responded to. I noticed that Liisa had tried both- putting in other
objects like cellphone, coins etc into the pocket trigger and also experimented
using it as cover over other objects. She tried stretching the fabric trigger but was
unable to get a feedback. After many attempts, she was relieved to get the LEDs
on by putting a metal spoon in the pocket. She also discovered that touching or
pressing a certain part of the pocket made the LED light up. She clearly identified
certain problems with the trigger showing that the pocket stretched too much
under the weight of common objects like a cell phone, and that the absence of a
handle or someway of fixing it to normal clothing discouraged her from carrying
this trigger out of the house. Although she had found some ways of ‘activating’
the trigger with a spoon or by pressing, she expressed her difficulty and little
frustration towards not finding a satisfactory and reliable interaction. She also
brought forward her surprise of not finding as many conductive objects as she had
expected to find around the house.
Figure 54. Some images taken
by Liisa of her interactions with
the soft trigger.
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It was clear that Liisa understood the form of the trigger and its affordances very
well. She was descriptive and deductive. She thought that this trigger could be a
device used to remotely control lighting in her room. However, it also became
apparent that the trigger had some problems as the the knitted object needed to be
stretched horizontally to an unnaturally high extent for the LED to come on. Also,
the first response of putting things into the pocket stretches it vertically rather than
horizontally, thus a pocket like this might create a better response if it sensed vertical
stretching rather than horizontal. Also, as the user herself pointed out, the mouth of
the knitted trigger was a bit less stretchy making it difficult to put bigger things into
the pocket.
These were clearly specific design issues that could be further developed for specific
devices or scenarios. However, the more interesting insights were regarding the
overall interpretation and process of understanding this unfamiliar fabric object.
One was that the pocket shape of the trigger created some expectations which were
identifiable and motivated Liisa to follow these expectations in her experiments. Thus
using other objects intuitively became part of the process, analysing their weight,
size or conductivity with respect to the trigger. Secondly, the trigger being a ‘new’
object, it took a lot of time and effort to just figure out how it worked. I felt that if I
had explained the working behind the trigger then her time would have been better
spent in creatively manipulating this ability of the trigger rather than only focusing
on turning the led on. This may not be the case for more coherent fabric devices, but
with a stand-alone fabric trigger some more introduction to the technical part was
probably needed.
2. Lauri
The soft trigger given to Lauri was the scroll type long fabric that could be
activated by hanging it over a metal bar. Three different LEDs could be turned on
by scrolling the fabric trigger around the metal rod. Learning from my experience
with Liisa, this time while introducing the fabric trigger to Lauri I also explained
this original intent and the working behind the prototype.
Lauri also had the trigger for a few days. His first associations with the trigger
was that it looked like a band-aid due to its colour and texture. He mentioned
that the trigger felt like part of a larger whole ripped out of its original context.
The soft stretchy nature of fabric assured him that it would not break easily and
thus encouraged him to experiment with stretching the material. He associated
numerous functions that could work with stretching of this knitted soft trigger
such as a band-aid that measures pulse rate or socks that warm up when worn. He
also imagined folding and squeezing as interesting interactions with the trigger.
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He tried different things to activate the trigger like connecting the conductive
parts on the knitted prototype with a wire or placing it on a metallic looking
surface which were not successful. Whereas hanging the trigger on a door handle
or squeezing it against a smaller conductive object worked well for activating
the trigger. He explained that squeezing the soft trigger to turn the LED on was
the most satisfactory interaction mostly because of the softness of the fabric and
the easy feedback of leds lighting up. He also identified the need for applying
pressure to make a good contact between the conductive portion of the trigger
and the metallic surfaces.
It was interesting to note that knowing the initial intention behind the design
and the working of the trigger, Lauri explored many other ways to activate the
trigger. He even had a preferred interaction, that of squeezing the artefact rather
then hanging it as initially intended. The LED coming on while squeezing the
soft trigger was mainly due to a mistake in wiring where one led was inversely
connected making the led come on when two conductive portions on the same
side of the fabric scroll touched. This resulted in a surprising feedback and
intuitive interaction of squeezing that the user discovered. Lauri had also tried
wrapping the soft trigger around objects and presented quite a wide range of
interpretations and interactions evoked by this fabric interface that went beyond
the initial design concept.
Figure 55. Some images taken
by Lauri of his interactions with
the soft trigger.
Reflecting on my interactions with the two users and their feedback led me to the
following insights:
The soft triggers embodied a clear indication towards needing other objects: Both users
interpreted the triggers as needing other objects to work and both tried to explore
the objects around their homes to find the ones that they thought could work with the
trigger. Both fabric prototypes had some design problems but the activity of giving
them out to others was largely successful as it brought forward the users’ perception
and interpretations of the soft trigger while they understood that the fabric artefact
was not itself an end product.
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Presenting simple yet challenging constraints: Presenting clear, simple but
challenging constraints in the form of physical affordances of the fabric triggers was
a valuable insight. Clarity and simplicity contribute to the transparency and the ease
of understanding the working of the trigger. Understanding the constraints led to
more innovative solutions. This was clearly seen when a soft trigger was given to
Liisa without telling her how it worked. She tried different things but was unable to
understand the working of the trigger and thus lost interest in the artefact. Whereas
in the other case, Lauri was told of the constraints and the intention behind how it
was thought to be used. He understood the constraints and yet was able to innovate
new ways to interact with the artefact that were totally different than those imagined
by me, the designer. Being an unfamiliar medium and being only parts of possible
interfaces, the soft triggers were not totally comprehensible, a little help and starting
points defined for the user helped them to take the concept much further.
Using the element of surprise: The unfamiliarity of the medium also played a crucial
role in raising curiosity and an interest to investigate and ‘play along’ with these
triggers. Surprise was also an important factor for motivation behind the interaction
with these soft triggers. As inferred by G.Bell et al. (2005) reflection is often triggered
by an element of surprise, where someone moves from knowing-in-action, operating
within the status quo, to reflection-in-action, puzzling out what to do next or why the
status quo has been disrupted. The accidental squeezing of the soft scroll trigger
created a surprising feedback of the LED coming on, which Lauri described as the
most satisfactory interaction. It was easy to achieve, consistent and fun and thus
encouraged interaction.
These were important insights that I learnt from and incorporated into the soft trigger
concepts designed afterwards. These two user tests were helpful and showed that I
was on the right track for evoking fabric oriented interactions while relating these
fabric artefacts to their surrounding objects.
10.3. Reviewing the prototypes in relation to the research questions
The two research questions that guided this project aspired to find ways or methods
of integrating electronics and fabrics that resulted in e-textile artefacts that were
specific to the medium of fabrics and enabled a dialogue, through interaction,
between the underlying artefact, the user and their environment. These two questions
found resolution in the assumption guided production process followed in this thesis
and the resulting soft trigger prototypes.
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The design and production process closely followed the fabric properties and actions
at every stage of the project. The process also studied everyday objects and identified
their physical properties that could work together with the fabric qualities to create
soft triggers that essentially needed other objects to work. Analysing and reflecting
on the characteristics of the resulting soft triggers showed that they evoked similar
interpretations of forms and materials than those we have with traditional knitted
fabrics. The prototypes also proved to invite their users to have an active dialogue
with their surrounding objects while interacting with the knitted soft triggers. These
reflections and insights justified the design process implemented in this project as
a way for creating e-textile interactions that are specific to the medium and engage
their users in an active dialogue with their surroundings. Below I explain these
characteristics of soft triggers in more detail to illustrate how they align to the design
process sought by the research query.
The process of integrating the two contrasting materials – electronics and fabrics – led
to medium specific design innovations:
Guided by the contrasting material requirements of fabrics and electronics, the
design process led to multiple iterations and experiments to find ways to integrate
their differences. This was a key factor in creating unique forms and techniques for
constructing the soft triggers. For example the need for insulating the soft wiring was
first solved by mimicking regular wires using knitted cables with conductive thread
running inside them. However, the inconvenient and obstructive nature of these
cables made it difficult to integrate with other knitted forms which led to innovative
reinterpretations of knitting techniques and construction to make channels or stitches
in the surface of the fabric triggers, hence pushing the designs forward from the
obvious to the unconventional.
The presence of small but visible electronic components such as LEDs or micro
controllers on the soft triggers were an instant give away, indicating that these fabric
artefacts were different from the usual ones. The obvious contrast in materials thus
assisted in pushing the concepts forward and also induced a sense of unfamiliarity
and curiosity. The unexpected results from familiar interactions added an element of
surprise. In Lauri’s case, the intuitive interaction of squeezing the soft fabric trigger
resulting in the fabric surface lighting up, was surprising and acknowledged as most
engaging.
Interactions with the soft trigger were motivated by fabric qualities but invited further
interpretations:
The soft triggers prototyped were proofs of concepts representing parts or units of
possible medium-specific fabric interfaces. Knitted fabrics were easily understood
as stretchable and in many cases, the interactions evoked by them were motivated
91
by this recognition of material properties and familiar forms. Both Liisa and Lauri
who were given fabric prototypes to keep, mentioned that they tried stretching the
fabric triggers and they knew that the knitted fabric would not break easily. Thus
following the fabric properties as stated in the assumption led directly to the design of
fabric triggers that were understood, through their appearance and interaction, to be
fabric-like. This made the interfaces approachable for the users to make associations
and draw interpretations that were related to fabrics rather than those of regular
electronic interfaces.
While the fabric material was familiar, the fabric trigger itself was not so much. This
part-unfamiliarity encouraged users to explore further. An example to explain this
aspect would be the soft trigger that resembles the bottom of a sleeve (see page 58)
and produces different results when the sleeve shape is folded up. The form evoked
a familiar action of folding or rolling up your sleeves. The sleeve shape did not have
to be attached to a traditional shirt to look or be understood as a sleeve. The soft
trigger thus, evoked a behaviour similar to a shirt sleeve which gave it a transparency
in interaction, but because it was not attached to a traditional shirt it needed to be
understood differently and had the openness to be reinterpreted in other ways.
Using other objects from the surroundings as essential to the interaction with the soft
triggers was one way to actively engage the user in a dialogue with her surroundings:
The soft triggers reacted to physical properties like weight, shape and conductivity,
thus could be activated by finding an object from their surroundings with the
appropriate physical attributes. In a home setting, each trigger could be activated in
multiple scenarios and using different things, thus highlighting their flexibility across
different use-cases. Sometimes interacting with the soft triggers revealed qualities of
objects, such as their conductive properties, which were otherwise not as apparent.
In the case of the pocket that responded to stretch and conductive objects, Liisa
expressed her surprise towards not finding as many conductive objects in her kitchen
as she had imagined. In these instances, it became apparent that designing fabric
triggers that reacted to other objects was a way to involve the immediate surroundings
while interacting with the triggers.
The user was encouraged to be an active participant to find different ‘solutions’
for activating the soft trigger. For example, the knitted legs could be activated in a
kitchen scenario by tying the required combination of legs on a metal handle bar of
a cupboard or knotted around the metal legs of a chair in the study. Thus the fabric
trigger provoked an immediate analysis and reinterpretation of surrounding objects
in order to use them appropriately with the soft triggers. This was an effective way to
create a relationship between the fabric artefact and its surroundings.
92
Thinking in a longer time frame, it might be that with trial and error the user identifies
certain objects that work best with the trigger and limit to only using these ‘tried
and tested’ objects. However, the process of getting to these conclusions itself would
be an interesting reflective process of reanalysing and appropriating objects. Thus
giving other objects roles other than the ones they normally play. Encouraging these
small enquiries was a way to motivate users to find creative ways to interact with their
surroundings.
11. Discussion: Space for user re-interpretations in
e-textile design
Taking familiar objects out of context or mixing elements and scenarios to engage the
viewer, provoke them or express a view point have been known strategies in art (for e.g
surrealism that played with reality extending its possibilities and fuelling imagination).
These tools have been used in design as well to bring forward the designer’s intention
or support a cause. Common examples are designs that use recycled materials –
chairs made from newspaper or paper roll cores. They use unconventional materials
to highlight an ideology – that of sustainability or recycling. The displacement of
objects from their natural environment thus gives a unique insight into alternate
interpretations and taps into one’s imagination. In a similar way, the fabric materials
that are part of our everyday lives can be thought to be a bit displaced from their
usual context of traditional clothing or furniture when made into e-fabric triggers. The
soft triggers emit the qualities of traditional knitted fabrics but embody additional
capabilities. Although they evoke similar interactions like stretching or pulling, they
could potentially work with different motivations and expectations. I found using
the two contrasting media – electronics and fabrics – was an important factor for
the mixing of familiarity and unconventionality and to play with the expectations
and curiosity of the users. The ‘strangely familiar’ as described by Betsy (2003) are
designs that have familiar forms but work in sophisticated ways. He discusses how
designing strangely familiar artefacts can be a way for human beings to be conscious
93
of the world they increasingly make in their image (ibid.). While Betsy argues for a
way of revealing the actual strangeness of the familiar through the strangely familiar,
it could also be used as a tool for making design approachable and yet surprising.
The strangeness is a positive quality that attracts people and invites them to interpret
it in their own ways.
In alignment with the discussions presented by Gaver, Beaver and Benford (2003)
about using ‘ambiguity’ to design engaging and thought provoking interactions, I
also found that a certain level of ambiguity in the process of designing the fabric
artefacts played an important role to bring forth reinterpretation and interactions.
Design is not always driven by needs only but also inspired by new technological
advancements. In this case, the invention of conductive yarns and fabrics made
it possible to explore different ways of using it with conventional fabric materials
to create unique interpretations and interactions. Thus the design process for the
thesis was guided only by materials and interactions keeping use and functions fairly
open. It was possible to make this separation between interaction and use at this
explorative level due to the nature of electronic interfaces. Unlike analog interfaces
that have a direct physical relationship between input and output electronic interfaces
‘interpret’ the input to an interface through an electronic circuit or software. This
also makes electronic interfaces more flexible, enabling one to design interactions
and experiences while keeping the output more ambiguous and user-dependent as
technically any task can be programmed to be executed corresponding to a desired
interaction. The functions mapped to the soft trigger interactions can be numerous
– some described by the test users were controllers for light in a room or ‘intelligent’
curtains and clothing, they could also be toys or musical instruments. This can be
researched further in dialogue with users and other actors involved and is not within
the scope of this thesis. However, what is interesting in the interaction design of the
soft triggers is the space it provides for interpretation. Some level of ambiguity with
respect to how to make the trigger work, enabled the user to adapt and invent ways
of doing so. In this case it would be by finding other appropriate objects that activate
the soft trigger. Ambiguity should of course, not be allowed to interfere with the
accomplishment of well-defined tasks but it can be used in some cases to engage the
user and to express the designer’s point of view while enabling the users of different
socio-cultural backgrounds to find their own interpretations (Gaver, Beaver and
Benford, 2003).
If we understand interpretation as the process by which users, non-users, and
designers come to assign meaning to the structures and functions of computational
systems at all levels of an interaction– from physical to evocative, then it is difficult
to understand interaction without interpretation (Sengers and Gaver, 2006). While
traditional Human-computer interaction studies believe that a specific preferred
interpretation should drive system design choices and used as a factor for measuring
94
the success of the design, Sengers and Gaver (ibid.) argue that technologies are
inherently interpretively flexible, and that people appropriate and reinterpret design
to deal with their varied everyday situations. They further explain that systems that
are open to interpretation enable people to play a more substantial role in actively
understanding both the system and its situation of use. I found by working with fabrics
and electronics, that they were an apt medium to design interfaces that encouraged
reinterpretations and innovativeness:
The soft triggers presented examples or snippets of interactions and experiences
with possible e-fabric devices or artefacts that exhibited certain affordances and
requirements while leaving room for interpretation and adaptation by the users. Often
designed objects or objects in the process of design go through the different stages of
being read and understood to find meaning and place in the world of their users. Akrich
(1992), in her paper about the ecosystem of technical objects presents the problem
of ‘inscribing’ the innovator’s vision of the world in the technical content of the new
object. Thus predetermining the settings that the users are asked to imagine for a
particular piece of technology without considering the practical sociological, political
and actual everyday dialogues the users will have with the object. She proposes
that one way of approaching this problem is to follow the negotiations between the
innovator and the potential users and to study the way in which these negotiations
are translated into technological form. Furthermore, one needs to go back and forth
between the points of view of the designer and the user, between the world inscribed
in the object and the world described by its displacement (ibid.). Having to find
other objects to work with the soft triggers was a way of making the fabric prototypes
flexible over different contexts. The soft triggers needed other objects to work but the
extent and nature of other objects to be adapted and used with them was completely
left up to the user. By opening out the possibilities of interaction with other existing
objects and connecting them to the surroundings gave room for interpretation and reappropriation. Following a similar argument as Akrich’s, the soft triggers that have a
level of uncertainty already designed into them, in this case the need to literally work
with surrounding objects, allowed for the negotiations between the different actors
present in the interactions. Making things open ended to an extent could assist this
adaptation and thus create a unique relationship with the user and her objects.
95
12. Conclusion and future development
The thesis project started from an interest to investigate the potential of using fabrics
as a medium for electronic interfaces, and a keen interest in ways of designing artefacts
that could engage its user in a creative dialogue with her environment. The process
guided me to study the everyday scenarios and ecosystems of fabrics and to sketch
many ideas of possible soft triggers that essentially incorporated physical properties
of surrounding objects to work. While following the properties of the medium, trying
to effectively integrate contrasting materials and including surrounding objects, a
number of soft triggers were prototyped that embodied different fabric related actions
and used physical properties such as shape or weight of objects to work. Interacting
with these soft triggers thus evoked intuitive fabric-oriented actions while their
unconventional appearance and behaviour raised the users’ curiosity, inviting them to
explore further. Interacting with the triggers also meant interacting with other objects
from the surroundings hence encouraging users to analyse, test and experiment with
their immediate environments to make the triggers work.
The resulting soft triggers were a reflection of the process that focused on interactions
and materials. Being only concept sketches, these soft triggers also possess the ability
to be scaled up or down as needed. They represent the variety of explorations and
working examples of e-textile interaction elements that can be produced following the
approach described here. The thesis however does not include the functions or tasks
that can be mapped onto these fabric triggers. Although these interaction elements
can be combined and modified to form more coherent interfaces, descriptions or
designs of actual soft devices produced by these methods are not covered in this
project, which rather focuses mainly on the process for designing fabric-friendly
interactions.
I see this project as a starting point for my future work in the field. I took an explorative
approach to build my skills and knowledge in the field of e-textiles and articulate my
point of view. Having done this work makes me excited and keen to delve deeper
into the field and develop more coherent soft devices or artefacts that can be part
of our everyday lives. The soft triggers produced were specific to the medium of
96
knitted fabrics. However the insights gained from the process of designing mediumspecific interactions, working with the constraints and opportunities of the traditional
construction tools and using fabric qualities to design for an active engagement with
one’s everyday surroundings, gave an understanding of the medium that is applicable
to any kind of fabrics.
Designing and working with knitted fabrics was a relatively time consuming process.
Apart from needing to learn how to work with the tools, a considerable amount of
handwork was required for putting knitted pieces together, insulating soft wiring,
stitching etc. Standardized plans and knitting drawings need to be made to help
duplicate and optimise the production of these soft devices by others. I feel that
sharing my process would help others interested to be more time efficient. I would
thus also like to develop my online project blog (www.defint.wordpress.com) further
in the near future by including tutorials, circuit maps and other resources from my
thesis work to share with those interested.
This project was self-funded and hence I was working with a small budget. I mostly
focused on using conductive yarns and threads. These materials were easily available
and in small quantities that allowed for an in-depth investigation. In the future, if I
have more resources, I would also like to experiment with other materials such as
conductive paints or light and temperature sensitive inks and printing techniques to
create soft interfaces.
The explorative process of working with materials and prototyping was extremely
engaging for me as a designer and gave many valuable insights. Having spent a lot
of time working individually with the medium, it would be interesting to further my
ideas and findings in a more collaborative environment. Brainstorming ideas and
working with designers from other fields like textile or product design would be an
opportunity to share my experiences and bring different perspectives and expertise
into the process of designing new artefacts or systems using this medium.
Working on the thesis gave me valuable material knowledge. The highly iterative
prototyping process made me aware of the opportunities and constraints presented by
fabrics as a medium for electronic interfaces. The e-textile soft triggers not only allowed
me to experiment with tools and techniques for combining electronics and fabrics but
also provided a lens to critically look at the traditional view of interaction design
and explore the role of play, ambiguity and accommodating user re-interpretations
in the design process. Although there are new technologies and intelligent materials
being researched, a large percentage of designers are still working with traditional
electronics and textile materials. This project shows the wide range of experiences
and interactions that can be designed with these basic materials. More over the new
97
fabric technology research can also align itself to the fabric specific approach taken
in this project to create technologies that enable a new language of interaction, which
is driven by textiles rather than merely copying the ones developed for traditional
electronic devices. I also hope this work to be of interest to other students and
amateurs in the field to learn from or take forward the ideas presented in the project.
98
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APPENDIX A
Some sheets from the scribble pads filled by Liisa and Lauri to record their interactions with the fabric triggers.
The scribble pads had mainly four questions:
1.
How would you describe the fabric object that you have been given?
2.
What interactions do you think will be possible with this object?
3.
Have you found a way to light the LED on the fabric object? Can you think of more ways or
places where it could work?
4.
Right now the interface output is indicated by lighting the appropriate LED. But lets stretch
our imagination a little. If this object could trigger anything, absolutely anything, what
would you want it to do?
102
Scribble sheets from Liisa
103
Scribble sheets from Lauri
104
105
APPENDIX B
Lilypad- Arduino codes along with the corresponding Processing sketches used to visualize the values from three
of the soft triggers.
Arduino code for the sleeve-like soft trigger (see
Page 58). The values are printed on the serial
that is read by the Processing sketch and interpreted to change the length of the blue bands
in the illustration.
int sensorPin = 0;
int ledPin = 13; // LED is connected to digital pin 13
int speakerPin = 11;
float sensorValue = 0;
int arraysize = 5; //quantity of values to find the median
//(sample size). Needs to be an odd number
long rangevalue[] = {
0, 0, 0, 0, 0};
void setup()
{
pinMode(sensorPin, INPUT);
pinMode(ledPin, OUTPUT);
pinMode(speakerPin, OUTPUT);
Serial.begin(9600);
}
void loop()
{
for(int i = 0; i < arraysize; i++)
{
rangevalue[i]=analogRead(sensorPin);
}
medSort(rangevalue, arraysize);
sensorValue = rangevalue[arraysize/2];
Serial.print(sensorValue);
Serial.print(“,”);
delay(1000);
// delay for 1 second
}
106
void medSort(long *a, int n) // function for noise reduction
// *a is an array pointer function
{
for (int i = 1; i < n; ++i)
{
long j = a[i];
long k;
for (k = i - 1; (k >= 0) && (j < a[k]); k--)
{
a[k + 1] = a[k];
}
a[k + 1] = j;
}
}
import processing.serial.*;
Serial myPort; // Create object from Serial class
String val;
// Data received from the serial port
float rectMax;
float rectTarget;
float rectCurr;
float speed = 0.01; //how fast to interpolate between rectCurr
and rectTraget
float sleeveVal;
float sensorMin = 1001;
float sensorMax = 1015;
PImage sleeve;
void setup(){
sleeve = loadImage(“graphics_sleeve.png”);
size(600, 800);
smooth();
rectMax = 900;
rectTarget = 0; // hte target height in the range 0..1
rectCurr =0; // the current height in the range 0..1
sleeveVal =0;
String portName = Serial.list()[0];
myPort = new Serial(this, portName, 9600);
}
void draw(){
background(255);
noStroke();
if(abs(rectTarget-rectCurr) > speed){
rectCurr += rectTarget>rectCurr ? speed : - speed;
}
translate(160,0);
scale(0.66);
image(sleeve,0,0);
rect(224,66,27,40+rectMax*(1-rectCurr));
fill(55,171,200);
if ( myPort.available() > 0) { // If data is available,
val = myPort.readStringUntil(‘,’);
// read it and store it
in val
if(val==null)
return;
try{
sleeveVal =Float.parseFloat(val.substring(0,val.length()-1).
trim());
println(val);
}
catch(Exception e){
}
}
rectTarget = sleeveVal<=0 ? 0: map(sleeveVal,sensorMin,sens
orMax,0,1);
}
Arduino code for the stretchy tube shaped
interface (see Page 64). The values are
printed on the serial that is read by the
Processing sketch and interpreted to change
the shape of the two parallel lines in the
illustration.
/* Built on - http://arduino.cc/en/Tutorial/AnalogInput */
int sensorPin = 0;
int sensorPin2 = 1;
int sensorPin3 = 2;
int ledPin = 13;
int ledPin2 = 12;
int ledPin3 = 11;
// variable to store the value coming from the sensor
int sensorValue = 0;
int sensorValue2 = 0;
int sensorValue3 = 0;
void setup() {
pinMode(sensorPin, INPUT);
pinMode(ledPin, OUTPUT);
pinMode(sensorPin2, INPUT);
pinMode(ledPin2, OUTPUT);
pinMode(sensorPin3, INPUT);
pinMode(ledPin3, OUTPUT);
Serial.begin(9600);
}
void loop() {
// read the values from the sensor:
sensorValue = analogRead(sensorPin);
sensorValue2 = analogRead(sensorPin2);
sensorValue3 = analogRead(sensorPin3);
//write the values in the serial for the processing sketch to read
Serial.print(sensorValue);
Serial.print(“,”);
Serial.print(sensorValue2);
Serial.print(“,”);
Serial.print(sensorValue3);
Serial.print(“.”);
//light the LED when strecthed beyond 200
if(sensorValue>200 ){
digitalWrite(ledPin, LOW);
}
else{
digitalWrite(ledPin, HIGH);
}
if(sensorValue2>200 ){
digitalWrite(ledPin2, LOW);
}
else{
digitalWrite(ledPin2, HIGH);
}
if(sensorValue3>200 ){
digitalWrite(ledPin3, LOW);
}
else{
digitalWrite(ledPin3, HIGH);
}
delay(100);
}
import controlP5.*;
import processing.serial.*;
Serial myPort; // Create object from Serial class
String val;
// Data received from the serial port
107
//sensor values
float Top = 0;
float Middle = 0;
float Bottom = 0;
float sensorMin = 5;
float sensorMax = 450;
//visualization point mapped coordinates
PVector pointTop;
PVector pointMiddle;
PVector pointBottom;
//point movement speed
float speed = 0.01;
//rest point horizontal coordinate
float restPoint;
//max distance from rest point
float maxDistance;
//Used to reflect drawing
PImage reflection;
//A chalk style brush
int brushSize = 10;
PImage brush;
void setup(){
size(800, 500);
smooth();
restPoint = width/3.0;
maxDistance = restPoint-30;
pointTop = new PVector(0,30);
pointMiddle = new PVector(0, height/2);
pointBottom = new PVector(0, height-30);
brush = loadImage(“brush_black_thin.png”);
String portName = Serial.list()[0];
myPort = new Serial(this, portName, 9600);
}
void draw(){
stroke(255);
noFill();
strokeWeight(5);
if ( myPort.available() > 0) { // If data is available,
val = myPort.readStringUntil(‘.’);
// read it and store it
in val
if(val==null)
return;
try{
String[] stretchValues = val.substring(0,val.length()-1).
trim().split(“,”);
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if(stretchValues.length > 0)
Top = map(Float.parseFloat(stretchValues[0]),sensorMin,
sensorMax,0,1);
if(stretchValues.length > 1)
Middle = map(Float.parseFloat(stretchValues[1]),
sensorMin,sensorMax,0,1);
if(stretchValues.length > 1)
Bottom = map(Float.parseFloat(stretchValues[2]),
sensorMin,sensorMax,0,1);
}
catch(Exception e){
}
}
background(0);
//update points position
if( abs(pointTop.x-Top) > speed ){
pointTop.x += pointTop.x<Top ? speed : -speed;
}
if( abs(pointMiddle.x-Middle) > speed ){
pointMiddle.x += pointMiddle.x < Middle ? speed : -speed;
}
if( abs(pointBottom.x-Bottom) > speed ){
pointBottom.x += pointBottom.x < Bottom ? speed :
-speed;
}
//draw curve
pushMatrix();
translate(restPoint,0);
beginShape();
curveVertex( -pointTop.x*maxDistance, pointTop.y );
curveVertex( -pointTop.x*maxDistance, pointTop.y );
curveVertex( -pointMiddle.x*maxDistance, pointMiddle.y );
curveVertex( -pointBottom.x*maxDistance, pointBottom.y );
curveVertex( -pointBottom.x*maxDistance, pointBottom.y );
endShape();
popMatrix();
imageMode(CORNER);
//copy left side of drawing and flip and past on the other side
reflection = get(0,0,width/2,height);
scale(-1,1);
image(reflection,-width,0);
}
void controlEvent(ControlEvent theControlEvent) {
if(theControlEvent.controller().name().
equals(“rangeController”)) {
// min and max values are stored in an array.
// access this array with controller().arrayValue().
// min is at index 0, max is at index 1.
sensorMin = theControlEvent.controller().arrayValue()[0];
sensorMax = theControlEvent.controller().arrayValue()[1];
}
}
Arduino code and Processing sketches for
the soft cushion-like soft trigger (see Page
62). The processing sketch responds to
the states of the trigger by colouring the
corresponding side of the illustration.
int ledPin = 11;
int vibPin = 13;
int switchPin = 16;
int switchPin2 = 14;
int switchValue;
int switchValue2;
void setup(){
pinMode(ledPin, OUTPUT);
pinMode(switchPin, INPUT);
pinMode(switchPin2, INPUT);
digitalWrite(switchPin, HIGH);
digitalWrite(switchPin2, HIGH);
Serial.begin(9600);
}
void loop(){
switchValue2 = digitalRead(switchPin2);
switchValue = digitalRead(switchPin);
if(switchValue == LOW){
digitalWrite(ledPin, HIGH);
Serial.print(“1,”);
}
else{
digitalWrite(ledPin, LOW);
Serial.print(“2,”);
}
if(switchValue2 == LOW){
digitalWrite(vibPin, HIGH);
Serial.print(“1.”);
}
else{
digitalWrite(vibPin, LOW);
Serial.print(“2.”);
}
}
import processing.opengl.*;
import geomerative.*;
import processing.serial.*;
Serial myPort; // Create object from Serial class
String val;
// Data received from the serial port
RShape shp;
PImage buttons;
int first = 0;
void setup(){
buttons = loadImage(“graphics_cushion22.png”);
size(buttons.width,buttons.height);
smooth();
RG.init(this);
shp = RG.loadShape(“graphics_cushion_no_circle.svg”);
shp = RG.centerIn(shp, g);
String portName = Serial.list()[0];
myPort = new Serial(this, portName, 9600);
}
void draw(){
background(179);
noStroke();
rect(0,0,width,height/3);
fill(100);
translate(width/2,height/2);
RG.shape(shp);
resetMatrix();
scale(0.80);
translate(15,87);
image(buttons,0,0);
if ( myPort.available() > 0) { // If data is available,
val = myPort.readStringUntil(‘.’);
println(val); // read it and store it in val
if(val==null)
return;
try{
String[] cushionValues = val.substring(0,val.length()-1).
trim().split(“,”);
if(cushionValues.length > 0) {
if(Integer.parseInt(cushionValues[0]) > 0){
shp.getChild(“blue1”).setFill(color(55,171,200));
}
else{
shp.getChild(“blue1”).setFill(color(255,255,255));
}
}
if(cushionValues.length > 1){
if(Integer.parseInt(cushionValues[1]) > 0){
shp.getChild(“green1”).setFill(color(136,170,0));
}
else{
shp.getChild(“green1”).setFill(color(255,255,255));
}
}
} catch (Exception e){ println(“OOOPS!!”) ; }
}
}
109
APPENDIX C
A set of videos showing the interaction and working of some of the soft triggers and components in the DVD.
110
Ramyah Gowrishankar
www.defint.wordpress.com
www.narrativize.net
111