Competition between Induced-Charge Electro-Osmosis and Electrothermal Effects at Low Frequencies around a Weakly Polarizable Microchannel Corner

Abstract

Microchannel corners are standard geometric features of planar microfluidic systems and lab-on-a-chip devices, so understanding their influence on flow within the channel is important for device design. The authors show that, depending on system parameters, ejection from a dielectric corner stems from competing nonlinear mechanisms: induced-charge electro-osmosis (ICEO) and electrothermal (ET) effects. Divergence from purely ICEO flow is a result of increasing ET effects due to Joule heating.