Theoretical analysis and experimental research of piezoelectric-electromagnetic hybrid vibration energy harvester

To address the concerns of single-mode energy harvesters' low output power and inefficient energy utilization, this paper proposes a novel piezoelectric-electromagnetic hybrid vibration energy harvester to enhance energy harvesting performance. In order to obtain the dynamic properties and evaluate the efficiency of the proposed hybrid energy harvester, an electromechanical coupling dynamic model was established, and the corresponding voltage, current, and output power of the hybrid energy harvester were calculated. The dynamical responses of the hybrid energy harvester obtained in the numerical simulations were discussed to reveal the influence of key parameters such as the excitation amplitude, load resistance, and initial magnetic distance. Then the validation experiments were conducted to verify the numerical simulation results. The results indicated that the excitation amplitude had a significant effect on the output voltage and output power. Meanwhile, the optimum load resistance and magnetic distance could boost the power generating performance of the hybrid energy harvester. The total output power of the hybrid energy harvesters can reach to 38.2 mW, which is 164.6% and 60.5% higher than those of the corresponding piezoelectric and electromagnetic energy harvesters, respectively. The results of this paper provide a new method for enhancing the performance of vibration energy harvester by means of hybrid energy conversion mechanism from an experimental and theoretical point of view.