Fabrication and performance of MEMS-based piezoelectric power generator for vibration energy harvesting

TLDR

The study presents a MEMS‑based piezoelectric power generator designed to convert ambient vibration energy into electrical power. The generator comprises a composite cantilever with a nickel mass, fabricated using sol–gel, RIE, wet etching, and UV‑LIGA techniques, and its performance was evaluated on a vibration test rig. The prototype resonated at ~608 Hz, producing 0.89 V peak‑to‑peak and 2.16 µW of power, demonstrating low‑frequency vibration harvesting capability.

Abstract

A MEMS-based energy harvesting device, micro piezoelectric power generator, is designed to convert ambient vibration energy to electrical power via piezoelectric effect. In this work, the generator structure of composite cantilever with nickel metal mass is devised. Micro-electronic-mechanical systems (MEMS) related techniques such as sol–gel, RIE dry etching, wet chemical etching, UV-LIGA are developed to fabricate the device and then its performance is measured on vibration testing setup. The investigation shows that the designed device is expected to resonantly operate in low-frequency environmental vibration through tailoring the structure dimension. Under the resonant operation with frequency of about 608 Hz, a first prototype of the generator result in about 0.89 V AC peak–peak voltage output to overcome germanium diode rectifier toward energy storage, and its power output is in microwatt level of 2.16 μW.