Optimal Design of an Electrothermal Microfluidic Pump

AC electrokinetics in microfluidic systems has been extensively investigated for its great potential in microfluidic pumping applications. The oscillating flow pattern in a microchannel with planar floor configuration restricts the pumping capacity due to the fast recirculating vortices over the electrode surface positioned in the microchannel floor. Patterned microgrooved floor in a fluidic microchannel can be employed to modify the flow pattern and make it uniaxial thus increase the net flow rate. Silicon KOH wet etching can be utilized to fabricate the microgrooved floor of the channel for its highly smooth surface quality and precise and reproducible configuration. We have developed an optimization methodology for the design of microgrooved configuration for a microfluidic pump using alternating current electrothermal (AC ET) actuation mechanism. The flow rate for the AC ET pumping system with optimized microgrooved floor can be higher as compared to the planar case without any significant increases of the temperature profile. In this paper, we are presenting the results of an optimum microgrooved floor configuration for an effective pumping application.