Performance Enhancement of Elastic-Spring-Supported Piezoelectric Cantilever Generator by a 2-Degree-of-Freedom System

Abstract

A piezoelectric cantilever generator using elastic springs as a supporting mechanism was fabricated for vibration-based energy harvester application. The optimum load resistance of 82 kΩ was selected to obtain the most effective output power. Two strong power peaks for the generator were obtained, being as high as 3.8 and 5.7 mW for frequencies of 68 and 79 Hz, respectively. This implies that the generator is controlled by a 2 degree-of-freedom system, which can induce a wide resonance frequency bandwidth. Therefore, the performance of the piezoelectric cantilever generator can be enhanced with the aid of the elastic spring for broadband energy harvesting.