Fig. 19.

a Schematic diagram of the preparation of Ca-alginate hydrogel microparticles by off-chip external gelation without pre-gelation. Droplets were generated using a microfluidic device assembled from fluoropolymer capillaries and a T-junction. Micrographs of b the channel outlet immersed in an aqueous solution of CaCl₂; Ca-alginate hydrogel microparticles prepared by collecting droplets in an aqueous solution of CaCl₂ at concentrations of c 1 wt% and d 0.1 wt%