AC Asymmetric Electrode Micropumps

The ability to move minute amounts of fluid around in a liquid circuit has become an increasingly important feature in current lab-on-a-chip systems. Several methods have previously been suggested, yet they lack the simplicity offered by the new and promising technique of Induced Charge electroosmotic pumping. In the present project, AC asymmetric electrode micropumps based on the principles of Induced Charge electroosmosis were designed and fabricated using standard cleanroom processing techniques. The micropumps were subsequently electrically characterized and a corresponding equivalent diagram model has been evaluated. In addition, a one dimensional model of a two electrode system has been analytically examined for an asymmetric electrolyte. Experimental flow velocities in the order of 140μm/s at 1.5Vrms corresponding to velocities of ∼ 0.5mm/s above the electrodes have been obtained. These velocities are compared with current theory. Furthermore, the parameter space of the micropump has been investigated and especially the effect of alterations in the applied voltage, the electrode translation period and the electrolytic concentration has been thoroughly studied.