Overview of electrohydrodynamic conduction pumping

This article describes an emerging fluid-flow generation and control technology, namely, electrohydrodynamic (EHD) conduction pumping. This pump is a nonmechanical-type pump based on the direct interaction of electric field and dielectric liquid. The driving force of the pump is the Coulomb force, and its free charge comes from the dissociation process of impurities or weak electrolytes in the liquid. In addition to the inherent advantages of EHD conduction pumps (such as intelligent active control via an electric field, absence of mechanical moving parts, simple design, light weight, suitability for special environments such as low-gravity spaces, and low energy consumption), EHD conduction pumps provide stable performance, long working life, and other unique advantages. In addition to traditional applications such as flow control, heat-transfer enhancement, and enhanced mixing, these conduction pumps have found a variety of innovative applications in the fields of micro-robot drive, wearable devices, and other fields in recent years. Currently, conduction-pump technology in the international community has gradually developed from macro-scale single-phase fluid to micro-scale multi-phase flows and has started to be tested in a low-gravity environment in orbit, which is expected for application in future spacecraft space-thermal management and other fields. However, research on electrohydrodynamics in China has started late, and studies on conductance-pump technology have been lacking. Therefore, this review introduces the EHD conduction-pump technology in detail from the aspects of its working principle, theoretical model, mathematical equations, research status, and recent progress, as well as in terms of future perspectives. © 2022 Chinese Academy of Sciences. All rights reserved.