Effect of Electrode Asymmetry on Performance of Electrohydrodynamic Micropumps

The effect of asymmetry in the electrode geometry and interelectrode spacing on the performance of ion-drag-type electrohydrodynamic micropumps was studied. The micropumps consisted of chromium/gold planar electrodes on a glass substrate that was integrated within a polydimethylsiloxane microchannel that was 100 mum in height. The pumps were tested using HFE-7100 as the working fluid for the maximum-pressure generation under a no-flow condition and the maximum flow rate under a no-back-pressure condition. The micropumps with an asymmetric-electrode design, where the emitter and collector electrode widths were different, generated a significantly higher pressure head and flow rate than the corresponding micropumps with symmetric-electrode designs for the same applied voltage. The power consumption of the pumps with asymmetric electrodes was significantly lower than that with symmetric electrodes.