Dimensionless Model of Electromechanical Coupling for Hybrid Piezoelectric and Electromagnetic Energy Harvester

In this paper, the influence of electromechanical coupling effect on performances of hybrid piezoelectric(PE) and electromagnetic(EM) energy harvester was investigated. The accurate expressions of output power and amplitude were derived. Then, the performances of harvester were studied and compared at the different coupling effects. The results show that the bigger coupling coefficient, the greater resonant frequency shift and output power; both in the situation of weak coupling and strong coupling, the performances of hybrid energy harvester are better than those of only PE or EM energy harvester. In addition, the optimal load resistance of hybrid energy harvester is related to the strength of coupling effect.