Vibration induced refrigeration and energy harvesting using piezoelectric materials: a finite element study

In this study, the bi-functional performance of a small-scale piezoelectric cantilever, which coupled piezoelectric and elastocaloric phenomena in a single device to produce energy harvesting as well as refrigeration effects due to vibration, has been investigated. Finite element modeling has been used to examine the performance of the device. The basic structure of the device is a cantilever that vibrates between two thermal bodies (hot and cold). The properties of BaTiO₃ (single crystal) were used to examine the bi-functional performance of piezoelectric cantilevers. In this study, different cases have been investigated, which are based on a number of cantilevers between hot and cold thermal bodies. When the number of cantilevers is one, the net cooling is 0.3 K and the power is 0.03 μW, while for four cantilevers, the net cooling is 1.2 K and 0.13 μW of power is produced. The results show that as we increase the number of cantilevers, a greater refrigeration effect is produced and higher power across the electrical load is achieved.

A device utilizing ambient vibrations to produce the required cooling effect as well as energy harvesting through elastocaloric and piezoelectric effects is demonstrated.