Interplay of induced charge electroosmosis and electrothermal flow in insulator-based dielectrophoresis

A depth-averaged numerical model is developed to understand the experimentally observed interplay of induced charge electroosmosis and electrothermal flow in an insulator-based dielectrophoresis microdevice. The experimentally measured nonlinear fluid velocity matches asymptotically the predicted velocity of the electroosmotic flow in a low-concentration buffer and that of electrothermal flow in a high-concentration buffer. This agreement is consistent with a scaling analysis.