Quantitative investigation of energy conversion in monolithic cantilever-based piezoelectric energy harvester

Vibrational energy harvesting is gaining more and more attentions recently due to increasing power demands for on-board and remote applications. Piezoelectric Zirconate Titanate (PZT) based cantilever structure is one of the popular forms for vibrational energy harvesting. However, due to its complex electromechanical characteristics, the energy harvesting still remains as a challenge. This paper intends to study the fundamental issues about piezoelectric cantilever harvester. Using the equivalent electrical circuit method, impedance matching is analyzed theoretically. The flapping test and weight test are carried out to investigate the electrical matching resistance and maximum conversion efficiency experimentally. Also the vibrator behavior loaded with a diode rectifier load is studied. The results indicate that these experimental methods are suitable to study the behavior of cantilever-based piezoelectric harvester, which quantifies the energy conversion issues of piezoelectric cantilever in the future vibrational energy harvesting.