Bio-inspired bistable piezoelectric vibration energy harvester: Design and experimental investigation

Inspired by the flight mechanism of dipteran, a novel bionic-dipteran energy harvester (BDEH) was proposed to collect ultralow-frequency vibration energy. Mimicking the skeletal structure of dipteran wing, two flexible beams and two rigid links are hinged together to form a bistable mechanism. Piezoelectric patches attached onto the flexible beams generate electricity as the proof mass is driven to oscillate by base excitations. A lumped-mass-spring model is built for theoretical analysis, which is verified by both finite element simulations and experiments. The dynamic responses of displacement and output voltage are achieved under different conditions, which indicate that the BDEH has the highest efficiency when the system undergoes cross-well vibration pattern. Both light damping and large excitation are beneficial to trigger cross-well vibration and thus enhance energy harvesting efficiency. A rectifier circuit is built to measure output power of the prototype under different excitations. Maximum power of 0.143 mW is generated under cross-well vibration pattern at an excitation frequency of 4 Hz and acceleration of 0.7g (g = 9.8 m/s(2)), which implies that the BDEH should be a feasible solution for ultralow-frequency energy harvesting even under low excitation. (C) 2021 Elsevier Ltd. All rights reserved.