UBC Theses and Dissertations

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UBC Theses and Dissertations

Scaling microfluidic 3D printing for hydrogels Melnick, Ryan Andrew


Reactive multilayer flow of alginate and calcium chloride was studied for the purpose of printing hydrogel structures. Particle image velociometery was used to capture the non-monotonic velocity profile of our three fluid layer printing process. Showing a separation of velocity profiles between fluid layers. Stability was studied under various flow regimes and reagent concentrations, where an unstable flow consisted of non-axisymmetric waves. Stable flow was found for all studied flow regimes at 0.75% alginate and 1.00% CaCl₂. Stability decreased with increasing calcium chloride or alginate concentrations. Dimensions of the printed hydrogel structures were controlled via regulating fluid layer flow rates. Printed structures were within the range of 7.4-10.8 mm outer diameter and 4.8-9.6 mm inner diameter. Time dependency of our printing process was examined by cycling between two stable flow regimes, demonstrating the hydrogel can be sculpted by flow rates alone. PMMA particles were encapsulated within an alginate hydrogel using our continuous printing process, producing capsules at 1.3 cm/s but not without variation in capsule size and position. It was uncertain whether this inconsistency is due to timing issues in our rotating pumps or physical mechanisms preventing more uniform capsule production.

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Attribution-NonCommercial-NoDerivatives 4.0 International