(416g) Inertial Microfluidics for Multifunctional Microgel Particle Fabrication

Microscale hydrogel (microgel) particles have broad utility in applications ranging from biosensing to drug delivery and regenerative medicine. To date, however, the fabrication of microgel particles has been somewhat crude and limiting to potential applications. Microfluidic lithography and microchannel emulsification have recently been shown to be quite powerful techniques for the fabrication of microgel particles with custom shape, composition and behavior. These traits make microfluidic fabrication an ideal strategy for multifunctional microgel formation via particle and cell encapsulation. These techniques suffer only from a lack of precision control over particles and cells within microfluidic flows. Inertial microfluidic focusing has recently been introduced as a high-throughput approach to particle and cell focusing. Inertial focusing exploits hydrodynamic forces arising from interactions between particles and surfaces and other particles. Lift forces, shear gradient forces and Dean drag forces are precisely controlled in microfluidic channels by geometric design to produce well-defined, predictable behavior that may be manipulated through microchannel geometry. We demonstrate the application of inertial focusing to microgel manipulation in microchannels as well as cell and particle focusing for controlled encapsulation within microgels. Focusing within viscous aqueous macromer solutions imposes additional kinetic constraints upon focusing, which must be balanced with the emulsification conditions. Applications for these unique particulate architectures will also be presented.