AN INVESTIGATION OF ELECTROWETTING-BASED MICROACTUATION

Electrical control of the interfacial tension between a liquid and solid (“electrowetting”) has been studied as a means of actuation in the microdomain (characteristic dimensions 1 /im-1 mm). Electrowetting provides a means of direct fluid pumping with no moving mechanical parts, which may prove useful in a number of application areas, most notably the liquid cooling of high-density microelectronic devices. A detailed model of a test device for the study of electrowetting is presented. The model describes liquid flow in a small channel, as governed as the Navier-Stokes equations, Young's equation, and Lippmann's equation (for the effect of an applied potential on interfacial tension). Simulation results are presented. Preliminary results indicate that electrowetting is a viable approach to microactuation: in a 10μm radius channel, it may be used to generate pressures on the order of 0.01 MPa, comparable to pressures generated by existing micropump designs, which are orders of magnitude larger in size. © 1990, American Vacuum Society. All rights reserved.