Vibration energy harvesting with a clamped piezoelectric circular diaphragm

With the rapid development of low power devices, the technology of energy harvesting has improved greatly. The performance of a PZT diaphragm energy harvester is demonstrated in this paper. Under an acceleration of 9.8 m/s2, a pre-stress of 1.2 N applied on the harvester, a power of 12 mW was generated at the resonance frequency of the harvester (113 Hz) across a 33 k ohm resistor. It was found that the energy from the harvester increases while its resonance frequency decreases when the pre-stress increasing. The contacting part between the proof mass and the piezoelectric disc was found another key element, which would influence the performance of the harvester. With its simple structure, the diaphragm harvester may push energy harvesting devices towards practical applications.