High Surface Area Reverse Electroactuation Energy Harvesting

Abstract

Manipulating a liquid droplet with applied electrical fields has long been studied and is known as electrowetting on dielectric (EWOD). In recent years, a new approach of energy harvesting that is related to EWOD has been demonstrated and it is termed reverse electrowetting energy harvesting or simply reverse electroactuation. Reverse electroactuation is opposite to electrowetting in which energy is generated by converting mechanical energy of the liquid motion into electrical energy. The amount of energy generated using this technique mainly depends on the contact area of the electrode-electrolyte interface. The contact area can be varied by applying a bias voltage to decrease the surface tension of the electrolyte resulting into a surface area increase. As an alternative, the contact area can also be varied by applying pulsating external pressure. In this study, we plan to model and experimentally demonstrate an AC current generation by applying pulsating external pressure to move the electrolytic fluid in and out of porous materials with high surface to volume ratio. The model is based on a simple solution to the Washburn equation which establishes the pressure dependency of fluid height in the pores. Various porous materials with both uniform and non-uniform pores are used in the analysis.