Piezoelectric cantilevers optimization for vibration energy harvesting

Vibration-based piezoelectric energy harvesters through the conversion of vibration energy to electrical energy has gained increasing attention over the past decade because of the reduced power requirements of small electronic components, especially in industrial condition monitoring applications where sensors may be embedded in machines. The structure parameters of cantilevered piezoelectric energy harvesters are of importance to maximize the output power in accordance with the characteristics of the ambient vibrations. Therefore, a piezoelectric cantilevers optimization method using finite element analysis and SPICE is proposed. This paper models piezoelectric cantilever using Hamilton principle and extracts the vibration modal parameters to establish the circuit model in SPICE. The numerical analysis is addressed to study the effect of parameters. Finally, the optimization analysis and experiment are carried out. The results verify that the optimized cantilevered piezoelectric energy harvesters can produce a 56V peak open-circuit voltage, and that the proposed method is suitable for optimization design of piezoelectric energy harvester.