Mixed electroosmotic-pressure driven multi-fluid flow in microchannels

Microfluidic and Lab-on-a-chip devices have attracted great interest over the last decade due to the advantages such as increased efficiency, throughput, portability, reduced analysis time, reagent consumption and cost. Comparing with a number of techniques (e.g., pressure, centrifuge, and thermal gradient driven flow), electroosmosis has been used to induce electroosmotic flow to transport, separate, and mix samples. This thesis addresses the following four topics: (1) Three-fluid flow in straight microchannels based on the combined effect of hydrodynamic and electroosmosis with planar interface; (2) Modeling of tunable optofluidic lens based on the combined effect of hydrodynamic and electroosmosis; (3) Semi-analytical model of mixed electroosmotic/pressure-driven two immiscible fluids with curved interface; (4) The linear stability of two-fluid flow in a microchannel and a parallel electric field.DOCTOR OF PHILOSOPHY (MAE