PIEZOELECTRIC ENERGY HARVESTING USING FOOTSTEPS

Abstract

The need for sustainable green energy is increasing. This has brought the use of human locomotion in harvesting alternative renewable energy to the forefront. The mechanical stress exerted on the ground when walking can be used as a source for electrical energy generation, in particular using a piezoelectric material. The piezo-electric material is electrically neutral as long as no stress is applied, but once a mechanical stress is applied, the balance is disturbed resulting in an external electric field, namely the piezoelectric effect. This paper presents a portable floor tile structure - StepGen, designed using piezoelectric plates to harvest the energy from human footsteps. Two major prototypes are presented, namely a rod-tap mechanism and a wheel-tap mechanism. The rod-tap mechanism uses a vertical rod array to strike the plates simultaneously and provides an average output of 1 mW per step with an approximate walking frequency of one-step per second. The wheel-tap vibration mechanism uses a chain system to rotate an array of wheels arranged on a shaft. Each wheel taps a plate simultaneously and provides an average power output of 5 mW at the same walking speed. The work demonstrates the feasibility of using piezoelectric technology for harvesting electrical energy and enhances the possibility of using improved piezoelectric material in the field of renewable micro energy.