Triboelectric Generators Production Using Cold Spray

Recently, vertical contact separation triboelectric generators have been proposed as a method of converting external mechanical energy into electricity. Placing these generators in a position to passively harness enough energy to power a sensor could reduce the dependence on batteries and recover energy that otherwise would be lost as heat. When two materials on opposite sides of the triboelectric series come into contact, charge transfer will occur according to the triboelectric effect. Charge will move between materials to equalize the electromechanical potential, leaving the two materials oppositely charged. Upon separation, the difference in polarity generates an electric field inducing a potential difference across the top and bottom electrodes. When the motion of these generators becomes periodic, alternating current signals will be continuously generated.

In this study, the cold spray process was utilized to produce the triboelectric layers necessary to build a simple and low cost tribogenerator. Aluminum and specialized polymer powders were deposited on copper substrates to produce the necessary layers. It was found that the roughness of materials deposited with the cold spray process added to the efficacy, a promising result for industrial adoption where low frequency alternating current is needed, such as in trackside sensors in railroad applications.