Development of a Compact, Low-Frequency Vibration, Piezoelectric MEMS Energy Harvester

Abstract

This paper presents the design and fabrication of a piezoelectric MEMS cantilever harvester of optimized shape able to generate a usable amount of power from low frequency vibrations for moderate cantilever deflection. The corresponding harvester design, obtained by means of FEM simulations, comprises a trapezoidal unimorph silicon cantilever beam with a piezoelectric PZT film and a rectangular silicon tip mass. This device was fabricated by wafer-level micro-fabrication processes. The harvester provided 2 μW generated power at 123 Hz resonant frequency.