Piezoelectric Transducers for Energy Harvesting: Electromechanical Model, Ambient Motion, and Electrical Loads

Harvesting ambient kinetic energy can power microsystems that cannot fit batteries large enough to sustain their operational life. Increasing the mechanical-to-electrical conversion efficiency of piezoelectric transducers (PZTs) is critical in this space. A good understanding of how PZTs react to motion and electrical loads is therefore necessary. This is especially true when ambient sources are irregular, which are more prevalent than the often-considered periodic vibrations, and for strongly coupled PZTs. This paper interprets and models PZTs with periodic and irregular sources and energy-harvesting loads. SPICE simulations show and compare the loads' effects on a strongly coupled PZT cantilever's motion.