Piezoelectric Energy Generation

This chapter reviews the field of mechanical energy harvesting using thin films. Mechanical modeling is used to predict the performance of energy harvesting systems. This is often done using a mass-spring-damper system to describe the harvester system. Three different types of electromechanical transducers are utilized to convert mechanical energy to electrical energy. They are schematics of electrostatic (capacitive), electromagnetic (inductive), and piezoelectric harvesters and the chapter compares these for vibration energy harvesting. The chapter further discusses two main approaches to improve the efficiency of power conversion from mechanical stress/strain to electric field/current: selection of the piezoelectric material and optimization of the mechanical design of the harvester. The piezoelectric coefficient and dielectric constant are key parameters that influence the performance of piezoelectric energy harvesters. Piezoelectric single crystals, ceramics, thick and thin films, and polymers such as poly-vinylidene fluoride (PVDF) are explored for energy harvesting for piezoelectric energy harvesters.