Numerical analysis of the effect of electrode arrangement on the performance of micro electrohydrodynamic conduction pump

As an advanced flow-drive technology, micro electrohydrodynamic (EHD) conduction pumps has become a new prospect in micro-scale industrial applications. This study numerically investigates the effect of electrode arrangement on the performance of micro EHD conduction pumps, focusing on inner spacing (s) and outer spacing (L) for configurations with one, two, and four pairs of electrodes. Simulations were performed with the OpenFOAM based on the finite volume method (FVM). The results reveal that reducing the inner spacing significantly enhances the net flow rate while decreasing the power consumption. The influence of the electric double layer (EDL), modeled via zeta potential (ζ), is more pronounced at smaller inner spacings, with negative ζ enhancing pumping performance and positive ζ potentially inducing negative net flow due to reversed charge density and electric force distributions. For series-connected electrode pairs, the outer spacing has little effects on the pumping performance. Parallel configurations with four pairs of electrodes achieve up to 160% higher flow rate, where the pumping performance benefits from the increase of the outer spacing. These findings provide critical design guidelines for improving the efficiency of micro EHD conduction pumps in applications such as microfluidics and electronic cooling.