Experimental Study of EHD Conduction Pumping at the Micro-scale

摘要

Electrohydrodynamic (EHD) conduction pumping is now a well-researched phenomenon that can generate fluid flow in dielectric liquids. It offers many advantages over other EHD pumping methods, such as no degradation of the working fluid and no need for a temperature gradient. Studies to-date have focused on macro-scale devices with applied voltages on the order of 10 kV. However, like many other EHD concepts, conduction pumping generation depends primarily on the intensity of the imposed electric field. Therefore, at the microscale the reduced physical scale can be accompanied by a reduction in the magnitude of the applied voltage. The simplicity of EHD conduction pumps, such as the lack of moving parts, make it an attractive method for pressure generation in microscale fluid and heat transfer devices. This experimental study considers an EHD micro-pump formed by a rectangular minichannel, 1 mm in height. Ten electrode pairs are arranged along the channel, flushed with the wall. The gap between the two electrodes of a pair is 250 microns, which is an order of magnitude less than previous studies. Static pressure head generation is measured along with power consumption. Pressure generation is achieved with considerably reduced applied voltage, and the ability of the pump to operate continuously over an extended period is also demonstrated.