Investigation of electro-osmotic micro-pumps using electrical field gradient and asymmetric micro-electrodes: numerical modeling and experimental validation

In present study, in order to fabricate AC electroosmotic micropumps, the improvement of geometrical parameters of 3D electrode, such as width, height and location of 3D steps on the base electrodes in one pair, the base electrodes size (symmetric or asymmetric), electrodes gap, and also electrical characteristics including voltage and frequency have been investigated. Also, the fluid flow (KCl) in channel was analized. The governing equations of fluid flow and electrical domain have been solved using finite element method to investigate the effect of electrode geometry on slip velocity, which affects the fluid flow. In order to validate our numerical simulation, this chip is fabricated by photholithography method such as deposition of platinum electrodes, creating 3D steps on the base electrodes using a polymer and fabrication a microchannel. Finally, Our results indicate that an optimal design results in a pump with the width (50 ) and steps height (5 ) of each electrode and their displacement (30 ) is capable of generating a high velocity, flow rate and pressure around 1.77 , 14.9 and 74.6 , respectively at a given voltage (2.5 ) and frequency (1 ), which qualitatively matches the trend observed in experiment. This design provides an improvement in electroosmotic pumping.