Ori-inspired bistable piezoelectric energy harvester for scavenging human shaking energy: Design, modeling, and experiments

Origami structure has nonlinear characteristics, which can broaden the vibration frequency band and improve the dynamic responses. By combining the origami structure with the piezoelectric theory, we can obtain a simple, portable, and bistable energy harvester that can be used to scavenge low-frequency vibration, such as human shaking. Therefore, an ori-inspired bistable piezoelectric energy harvester is proposed. The mathematical model of the harvester is established based on the energy method and Lagrange equation. Dynamic responses and harvesting characteristics are explored by theoretical and experimental methods respectively. Comparing the theoretical and experimental results, the rationality of the established mathematical model is verified. The output performance of the harvester is enhanced by increasing the external energy input and reducing the damping coefficient. On the other hand, by increasing the length of the connecting rod, the harvester can obtain higher output performance at the cost of discarding the bandwidth of interwell vibration. In the experiment, when the excitation acceleration is 1.2 g and the frequency is 6.2 Hz, the ori-inspired harvester could have the root-mean-square voltage of 25.7 V and output power of 2.2 mW at a resistance of 0.3 MΩ, which has great potential to provide continuous power for condition or biological monitoring equipment.