Simple in fabrication and high-performance electrohydrodynamic pump

Abstract

One of the most promising applications of electrohydrodynamic (EHD) pumps occurs at the microscopic scale. However, microscopic dimensions do not always imply microscopic characteristics, and stringent requirements are sometimes imposed on the values of certain variables—for instance, a flow rate of the order of 10 ml/s and a pumping pressure of 100 kPa. This study proposes an EHD pump system based on a holed metal-clad insulation barrier pair that generates high-performance characteristics. A feature of the system is the focusing of electric field lines inside the holes, which increases the electric field strength and activates charge formation processes. Dodecane with 10% Span 85 was used as the working dielectric liquid with a conductivity of 8 × 10−9 S/m. The Onsager effect is believed to be the dominant charge formation mechanism in the pump with some injection contribution. We measured the characteristics of the electric current (curves of current–voltage and current–time) as well as the performance-related characteristics of the pump in experiments (curves of pressure–voltage and flow rate–pressure at different voltages). The scalability of the flow rate of the proposed EHD pump was investigated by comparing single-hole and nine-hole configurations. As a result, a non-linear growth of the pump performance on the number of holes was obtained, with the distance between the holes comparable to the inter-electrode gap. The estimated flow rate and pressure for the proposed modulus EHD pump with dimensions of 1 cm3 can reach values of 82 ml/s and 620 kPa, respectively.