A FREQUENCY ADJUSTABLE VIBRATION ENERGY HARVESTER

Abstract

This paper presents a new method for the frequency adjustment of piezoelectric vibration energy harvester. The structure of the new design consists of a piezoelectric cantilever, and a gravity center movable mass. The resonant frequency of the cantilever can be adjusted by changing the gravity center of the mass. An approximate formula for the frequency evaluation is induced, which shows the resonant frequency strongly depend on the gravity center of the mass. FEA model is built for the simulation of frequency adjustment. A prototype is setup for the verification of the method, and the measurement results show that the resonant frequency of the prototype can be adjusted from 130 Hz to 180 Hz.