Improving voltage output with PZT beam array for MEMS-based vibration energy harvester: theory and experiment

Piezoelectric vibration energy harvesters as an autonomous power source for various types of sensors, actuators and MEMS devices have attracted increasing attention in recent years. Traditional MEMS-based PZT single beam vibration energy harvester has low voltage output (usually <1 V) which causes rectifier circuit to consume most of power or turn off in practical applications. In this paper, in order to improve the voltage output of MEMS-based PZT vibration energy harvester as well as ensure high power output, a PZT beam array configuration for MEMS-based vibration energy harvester is proposed. Based on Hamilton’s principle and Euler–Bernoulli beam theory, mathematical model for the proposed vibration energy harvester is established. Two different dimensions MEMS-based PZT beam array vibration energy harvesters are designed and fabricated through micro-fabrication techniques. The performances of the two types of fabricated vibration energy harvesters are characterized and compared with traditional vibration energy harvester in experiment. Experimental results agree well with theoretical analysis, and the experimental results show that the better performance fabricated vibration energy harvester can generate 121.4 μW and 3.5 V respectively at 1 g acceleration.