Performance of Piezoelectric Stack for Energy Harvesting from Low Frequency Vibration

Piezoelectric energy harvesting is a new type technology of clean energy.The output voltage and power equations of piezoelectric stack in 33-mode low frequency vibration were derived,which shows that the output power and voltage are positively correlated to the piezoelectric coefficient,thickness and number of patches,load resistance,exciting force and frequency,yet negatively correlated to electrode area and dielectric constant.Besides,higher output voltage can be got from serial piezoelectric stack while higher current and power can be generated by parallel one.The results were verified by the experiments conducted on PZT-43 type piezoelectric stack with a novel holding device.The maximum output power of serial stack and parallel stack in two piezoelectric patches are 0.14μW and 0.4μW respectively under the conditions of 5Hz frequency and 26N force.The measured trend of output voltage changing with the vibration frequency,the number and thickness of patches and the electrode area correspond with theoretical forecast.