Heat Transfer Enhancement Measurement for Microfabricated Electrostatic Fluid Accelerators

Air cooling, because of its simplicity, remains as the most popular cooling solution for microelectronics in the consumer market. However, the trend of increasing heat generation in microelectronics and the demand for compact devices result in heat fluxes approaching the limit of conventional rotary fan air cooling technology. Electrostatic fluid accelerators (EFAs), also known as electrohydrodynamic (EHD) ionic wind pumps, have the potential of becoming a critical element of electronic thermal management solutions. In this technique, application of voltage to a sharp electrode ionizes air molecules, which are propelled by the electric field, transferring part of their energy to neutral air molecules, thus creating airflow and cooling. The airflow, so called ";corona wind";, can be used discretely for hot spot cooling or integrated into a compact thermal exchange surface to decrease the fluid boundary layer and increase heat transfer enhancement. The EFA investigated in this study consists of a microfabricated AFM-cantilever corona electrode using combination of deep reactive ion etching (DRIE) and reactive ion etching (RIE), and a flat collecting electrode that doubles as the thermal exchange surface. The fabrication and testing results of a microfabricated EFA are presented in paper. Free and EFA-enhanced forced convection heat transfers are both reported by measuring the heating power difference of the collecting electrode under constant surface temperature.