Toward Hybrid Energy Harvesting by Piezoelectric and Pyroelectric Materials Using Synchronized Switch Harvesting

Harvesting energy from such renewable energy resources as solar, vibration, thermal and magnetism in microelectromechanical systems has gained much attention from researchers in recent decades. From among these resources using piezoelectrics and pyroelectrics due to their ease in the design and implementation has attracted more attention. In this paper, a new harvesting technique has been considered, which uses piezoelectrics and pyroelectrics simultaneously. The concept of method and theoretical analysis for hybrid energy harvesting method is presented and then by exerting vibration and heat forces, the average harvested power is determined. This investigation has been done by considering PZT and PMN-0.25PT ceramics as smart elements. Different strategies for switching have been considered in synchronized switch harvesting method and then the best switching between these three strategies—switching on voltage, mechanical displacement or temperature amplitude—is introduced. In each condition, the positive influence of hybrid method has been as compared with piezogenerators for both smart elements. The effect of four important parameters—temperature amplitude, vibration amplitude, inversion coefficient, and equivalent load resistance—is examined. The most effective switching method and material are proposed in the final part of the paper.