Electric current generation of a droplet falling into an electrolyte solution

Abstract

A novel system which can greatly improve the waving potential [1] of metal produced by a moving liquid–solid boundary is presented in this paper. By using a pair of copper electrodes immersed in an electrolyte solution, a significant electric potential is generated by changing the wetted surface area of only one electrode when a droplet falls into the electrolyte solution. Experiments show that the electric potential difference between the two electrodes is generated due to different wetted areas at the two electrodes. The magnitude of the generated electric current depends on the types of the electrolyte solution and the moving speed of the air-electrolyte solution interface. A droplet of 24 µL can generate a waving potential of three orders of high than that reported in the reference paper [1]. The approach of inserting a pair of asymmetrically insulated metal electrodes into an electrolyte solution makes it possible to utilize ordinary pure metal materials for harvesting waving potential energy from a dynamic moving liquid–air interface.