Functional microgels tailored by droplet-based microfluidics.

Monodisperse polymer gel particles with micrometer-scale dimensions serve for a variety of applications, including those as microcapsules for actives or as micrometer-sized matrixes for mesoscopic additives. These particles can be produced with exquisite control through the use of droplet-based microfluidic templating followed by subsequent droplet solidification. This can be achieved by two ways: One way is to use pre-microgel solutions of low molecular weight monomers and to form microgels by polymerizing these monomers. Another way is to use pre-polymerized, high molecular weight precursors and to gel them by polymer-analogous crosslinking. Both approaches have their specific advantages, allowing microgels to be tailored and optimized for specific needs such as those as delivery systems or scaffolds for living cells. This article highlights some recent achievements in the development and use of these microfluidic techniques to fabricate functional microgel particles.