Performance Analysis of Varied Dimensions Piezoelectric Energy Harvester

Abstract

Thin film piezoelectric material plays a vital role in micro-electromechanical systems (MEMS), due to its low power requirements and the availability of high energy harvesting. Zinc oxide is selected for piezoelectric material because of its high piezoelectric coupling coefficient, easy to deposit on silicon substrate and excellent adhesion. Deposited ZnO and Al improve the electrical properties, electrical conductivity and thermal stability. The design, fabrication and experimental test of fabricated MEMS piezoelectric cantilever beams operating in d33 mode were presented in this paper. PVD (Physical Vapor Deposition) was selected as the deposition method for aluminium while spincoating was chosen to deposit ZnO thin film. The piezoelectric cantilever beam is arranged with self-developed experimental setup consisting of DC motor and oscilloscope. Based on experimental result, the longer length of piezoelectric cantilever beam produce higher output voltage at oscilloscope. The piezoelectric cantilevers generated output voltages which were from 2.2 mV to 8.8 mV at 50 Hz operation frequency. One of four samples achieved in range of desired output voltage, 1-3 mV and the rest samples produced a higher output voltage. The output voltage is adequate for a very low power wireless sensing nodes as a substitute energy source to classic batteries.