A wide band nonlinear dual piezoelectric cantilever energy harvester coupled by origami

Abstract

Since the traditional linear piezoelectric vibration energy harvester has narrow energy conversion frequency band and low energy conversion, a wide band nonlinear dual piezoelectric cantilever energy harvester coupled by origami is proposed. Apart from using two piezoelectric cantilevered beams to broaden the working frequency band of the device, the nonlinear origami component is introduced into the upper and lower beams to realize the dynamic coupling of the two piezoelectric beams. The origami structure can change the stiffness and increase the nonlinearity of the system by dynamic folding, so as to further broaden the frequency band and increase the output power. The structure of the proposed energy harvester is designed. Based on the Euler Bernoulli beam theory, Hamilton principle and the dynamic analysis of origami component, the electromechanical coupling dynamic model of two piezoelectric beam subsystems is established, and the approximate solutions of the output voltage and output power of each subsystem are obtained by harmonic balance method. The numerical simulation of each subsystem is implemented by the Runge–Kutta method, and the influences of excitation frequency and amplitude on the output voltage and power of each subsystem are explored respectively. The results show that this energy harvester that has a nonlinear characteristics of hardening stiffness can significantly broaden the working frequency band of each piezoelectric beam, and the maximum voltage value is about 1.2 V. Via the simulated analysis of motion, it is further proven that the proposed energy harvester has strong nonlinear characteristics. Furthermore, the coupling position of origami component on the voltage output is explored and the optimal coupling position is determined. Finally, the experimental results show that both of two beams can obtain effective voltage output between 0.5 and 0.6 V in the frequency range of 0–50 Hz, which validates the effectiveness and correctness of the simulation model.