This research investigates the micro-encapsulation process with a
pressure-type micro-atomizer. Alginate and CaCl2 aqueous solution are used
as the membrane material and hardening agent, respectively. The high speed
images were taken to investigate the formation processes of the
microcapsules. Results show that the geometric shape of the microcapsules
was sensitive to the droplet flying distance and the concentration of alginate
aqueous, but insensitive to the concentration of CaCl2 aqueous. Results also
show that the membrane thickness of the microcapsules was controlled by
the diffusion processes of calcium chloride. An empirical formula was
derived to describe the rate change of the membrane thickness in the
hardening processes.