Electrode Arrangement for Micro-Scale Electrohydrodynamic Pumping

Abstract

An experimental investigation is conducted to develop an electrohydrodynamic (EHD) pump based on microelectromechanical systems (MEMS) technology. In EHD conduction pumping, Coulomb force is the main driving force for fluid motion. The non-equilibrium process of dissociation and recombination of dielectric liquid, HFE-7100, produces hetero-charge layers in vicinity of electrodes. The attraction between the hetero-charge layers and electrode surfaces generate the net motion in the dielectric liquid by applying asymmetric electric fields. In order to generate the asymmetric electric fields, two electrode plates are prepared. On one plate, an electrode pattern is designed as a series of planar micro scale comb fingers. The other electrode plate is a non-patterned plane surface. The working fluid is confined between the two electrodes which face each other. The generated pressure and the liquid flow rate are measured for the different asymmetric electric fields. The validity of the conduction pumping mechanism is confirmed by experiments.