Improvement for Pressure Performance of Micro-EHD Pump with an Arrangement of Thin Cylindrical Electrodes

A micro-electrohydrodynamic (EHD) pump is experimentally tested. In order to improve the static pressure performance, the EHD pump examined in this paper was fabricated with a series of thin stainless steel wires (the outer diameter is 0.3mm). The overall dimensions of the EHD pump were 30×30×4.9mm and of the pumping channel were 24×24×0.9mm. An electrode pair consisted of one emitter electrode and two collector ones. The five sets of pumps were prepared for experiment. Those pumps were consisting of the number of electrode pairs from 1 to 5. The static pressure is measured with dibutyl-sebacate as a working fluid which has a dielectric constant, ε/ε_0=4.8 and a low electric conductivity, σ=4.7×10^<-10> S/m. The experimental results are compared with the theoretical results. In the theoretical model, the pressure is generated by Coulomb force which forces to move the unipolar ions in the high electric field. The experimental results indicate that the pressure increase as the number of electrode pairs increases and is generated up to 350Pa at an applied voltage of 1kV with 5 electrode pairs. Also, the experimental results show a good agreement with the theoretical ones. It is found that the theoretical model is useful for design of the high performance EHD pumps.