Design, fabrication, and experimental demonstration of a piezoelectric cantilever for a low resonant frequency microelectromechanical system vibration energy harvester

Abstract

We compare the performances of vibration-powered microelectromechanical system (MEMS) electrical generators using a Pb(Zr, Ti)O-3 (PZT) material. With the aid of a finite element method simulation, we have designed a PZT cantilever-based energy-harvesting system that uses mechanical vibration. We fabricate cantilevers on the MEMS scale with an integrated variable Si proof mass to obtain a low resonant frequency and high current. Based on simulation results, we fabricate cantilever devices with integrated Si proof masses with volumes of about 0.32 and 0.53 mm(3). These devices compare favorably to the data obtained through simulation. Further, by comparing variable mass volumes, we obtain a high current and low resonant frequency. Similar results are obtained by simulation and experiment. Therefore, we offer a new and predictable means of obtaining a low resonant frequency for application to a micropower source area. Furthermore, from the size effect of the proof mass volume, we obtain the current and resonant frequency of these energy harvester systems. The possibility of a MEMS-scale power source for energy conversion experiments is also tested. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JMM.11.3.033009]