Thermomechanical Effects on Electrical Energy Harvested from Laminated Piezoelectric Devices

Abstract

Piezoelectric materials are used to harvest ambient mechanical energy from the environment and supply electrical energy via their electromechanical coupling property. Amongst many intensive activities of energy harvesting research, little attention has been paid to study the effect of the environmental factors on the performance of energy harvesting from laminated piezoelectric materials, especially when the temperature in the operating condition is different from the room temperature. In this work, thermomechanical effects on the electrical energy harvested from a type of laminated piezoelectric devices, known as thin layer unimorph ferroelectric driver (called THUNDER) were investigated. Three configurations of THUNDER devices were tested in a controlled temperature range of 30–80 °C. The THUNDER devices were pushed by using a cam mechanism in order to generate required displacements and frequencies. The experimental results exhibited a detrimental effect of the elevated temperature on the generated voltage and the harvested electrical power. It is due to changes in residual stress and geometry. These results are advantageous for many applications of the THUNDER devices and for future design of a new laminated piezoelectric sensor and energy harvester in an elevated temperature environment.