Induction electrohydrodynamics micropump for high heat flux cooling

Abstract

Induction electrohydrodynamics (EHD) has been investigated as a possible means of pumping liquids through microchannel heat sinks for cooling microprocessors. A pump utilizing induction EHD has been microfabricated and tested. The experimental results matched the predictions from correlations to within 30%. Based on this, a micropump has been designed which is miniaturizable to a level where it can be integrated into the microchannels. The micropump utilizes a vibrating diaphragm along with induction EHD for pumping. The vibrating diaphragm does not cause any net flow by itself but causes high local bulk fluid velocities which lead to an increase in the power drawn from the electrodes and an increase in efficiency of EHD, both of which lead to a higher flow rate. The performance of the pump is predicted using an experimentally validated numerical model. The numerical model solves the three-dimensional transient fluid flow and charge transport problem due to simultaneous actuation of EHD and the vibrating diaphragm. Numerical results for micropumps integrated into trapezoidal microchannels are presented. The results indicate that the proposed micropump design has significant potential for microelectronics cooling applications: It is easy and inexpensive to fabricate, needs no added space, and can achieve the high flow rates needed.