Abstract
In a microfluidic device, utilization of electrokinetics is effective for particle control. Under high frequency alternating-current (AC) electric field, the control of particles can be achieved in the condition with low voltage. In this study, we focus on electrothermal flow subjected to AC electric field. A lateral observation system with a minute prism has been developed in order to measure the velocity field normal to the substrate. In this system, clear particle image can be obtained by using the PDMS (polydimethylsiloxane) channel with the side wall thickness of 125μm. It is observed that the particle velocity in the vicinity of electrode edge with 20 V_<P-P> at 300 kHz is 75 μm/s. This result indicates that the electrothermal effect is valid for controlling the fluid with high electric conductivity.
