3. Flow and Aggregation Characteristics of Thermo-responsive Microgels During Phase Transition

The flow characteristics and kinetic characteristics during the phase transition may directly affect the performance of thermo-responsive microspheres in many applications. In this chapter, to probe into the flow and aggregation behaviors of thermo-responsive microspheres in microchannel during the phase transition, the flow characteristics of monodisperse poly(N-isopropylacrylamide) (PNIPAM) microspheres in microchannel with local heating are introduced systematically. Furthermore, the effects of microchannel surface wettability and roughness on the flow behaviors of thermo-responsive microspheres during the phase transition are also introduced. The phenomena show that the microspheres can aggregate together during the phase transition and stop automatically at a desired position in the microchannel by local heating if designed properly, which is what the targeting drug delivery systems expected.