Figure 2.

(A) A simple diagram showing a droplet microfluidic system, in which a droplet microfluidic chip is used to generate droplets that are subsequently cured in a 2% CaCl₂ gel to yield microcapsules [68]. (B) A schematic diagram of droplet microfluidic technology [69]. (C) An optical micrograph of the microparticle encapsulation process. (D) Following water-in-oil particle settlement and acidification using an acidified oil, the oil layer and the acidified oil are removed from the droplets, after which CaCl₂ is added to crosslink and solidify the alginate ions, thereby generating microspheres with a core–shell structure [70]. (E) A schematic diagram of a device used to produce microcapsules via microfluidic electrospray [71].