Dynamic Behavior of Membrane-Bound Capsules Christopher Blais and Nivedita Gupta Department of Chemical Engineering Aspiration Experiments Motivation Capsules occur in various applications Capsule Deformation Studies 9.86 kPa • Food • Carbonless Paper • Cosmetics • Textiles • Pharmaceuticals • Living cells 13.9 kPa Syringe containing capsules Axisymmetric PDMS Channel High Speed CMOS Camera Capture Syringe pump set to 1-5 mL/s Deformability of diseased cells as a diagnostic tool 𝑅𝑐 1 𝑅𝑐 ∆𝑃 = 2𝑇 ( − 𝑅𝑝 ∆𝐴 = 2𝜋[𝑅𝑝 ∙ ∆𝐿 1 − ] 𝑅𝑐 1 ) 𝑅𝑝 𝐿 Process Waste 𝑅𝑝 Data Analysis in Vision assist and Matlab 𝑇 = K ∙ ∆𝐴/𝐴0 𝑑𝑑 𝜅= 𝑑𝑠 10 5 mL/min Isotropic Tension (N/m) Bow et al., Lab on a Chip 11, 1065 (2011) A T 168.4 A o 1 for 60 0.03 A T 504.1 A o 30% HSA 0.01 HSA 0.1 Area Dilation (ΔA/Ao) 0.02 -2 -1 0 1 2 Reaction Time 10 min 20 min 30 min 60 min 23 Frequency 13 6 Crosslinking Reaction in Terephthaloyl Chloride forms membrane Dropwise addition of HSA solution in Silicon oil with magnetic stirring Store capsules in Isotonic Saline Solution 0.3-0.4 0.4-0.5 0.5-0.6 0.6-0.7 Capsule Diameter (mm) 6 4 0.7-0.8 0.8-0.9 5 -3 -2 -1 Centermass (mm) 0 1 2 20% Robust capsules with 20 minute reaction time and 20 – 30% HSA Constant drop size and uniform membrane thickness with T-junction method Channel Diameter 250 µm 4 5 30% HSA capsule shows negligible deformation • Robust capsules for 20% - 30% HSA solution with 20 minute reaction time • Compressibility modulus for 25% HSA capsules was 168 N/m and 30% HSA capsules was 504 N/m • Preliminary experiments set up for drop deformation through a sudden contraction • Compare capsule behavior to numerical simulations • Experiment with other Proteins or polymers Drain Bulk and wash with IPA and DI Water 3 Centermass (mm) Future Work HSA Solution 1 µL/min Store capsules in Isotonic Saline Solution 4 30% Average diameter ~ 0.4 mm Silicon Oil 1 µL/min Crosslinking Reaction in Terephthaloyl Chloride forms membrane 0.2-0.3 5 Polydisperse distribution of capsules using emulsion method T-junction Method HSA Drop formation at TJunction HSA Concentration 10% Drain Bulk and wash with IPA and DI Water 3 Summary Emulsion Method Add Terephthaloyl Chroride 20 0 Fabrication and Optimization of HSA Capsules 15 30 10 0 Compressibility modulus for 30% HSA capsules larger than for 25% HSA capsule 40 0.01 -3 • Compare deformation of capsules translating through a sudden contraction with numerical simulations 𝐿−𝑊 𝐿+𝑊 50 0.1 0.001 modulus 𝑊 Δ = 𝐿 0.04 25% HSA compressibility 30% HSA Velocity (mm/s) • Fabricate robust capsules made from Human Serum Albumin (HSA) Deformation Parameter, Goals of Research • Measure area capsules k = 0.65 dd T-junction can be scaled from 50 mm to 1 mm in size Droplets not spherical due to nonNewtonian HSA solution • Bovine serum albumin • Alginate Acknowledgements UNH Hamel Center for Undergraduate Research Robert Carroll (PhD 2014 UNH) Brian Zukas (MS 2014 UNH; PhD 2016 UNH)
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