The Optimum Design of Traveling-Wave Electroosmotic Micropumps

Abstract

This study investigates the performace of electroosmotic micropumps with arrays of microelectrodes for pumping electrolyte in a microchannel. Traveling-wave potentials are applied to the microelectrode arrays. Ions accumulate in the double layer in response to the applied signal. The electric field acts on the charge pulling the fluid in the direction of the traveling wave. In this study, the effects of the widths and heights of the electrodes, the gap size between the electrodes and the frequency of the applied traveling-wave potential on the pumping velocity of the micropump are investigated in order to obtain the optimum design of the micropump. The optimum operating frequency of the traveling-wave potential is about 1 kHz for the micropumps with different electrode widths and gap sizes. The pumping velocities increase with the decrease of the electrode widths and gap sizes for the micropumps. For the micropumps with different electrode widths and gap sizes, it is found the optimum electrode heights are about 5.5 μm when the gap sizes are less than the electrode widths, and the optimum electrode heights are about 10.4 μm when the gap sizes are greater than the electrode widths.