Vibration hybrid energy harvester using magnetic levitation based on flapping-wing motion mechanism

Abstract

Vibration energy harvesting technology can convert the vibration energy widely existing in the environment into electrical energy and provide an energy supply for microelectronic devices. Incorporating piezoelectric and magnetic levitation effects into the mechanism of flapping-wing motion of Diptera insects, a bio-inspired structure for ultra-low-frequency vibration energy harvesting is proposed. A flexible cantilever beam mounted with piezoelectric fiber sheets simulates a wing, and magnetically levitated magnets inside a levitation tube with an inversely moving coil constitute a forced oscillator, which can be combined to simulate the flapping-wing motion of Diptera insects. The energy harvester can achieve the effect of single vibration excitation-multiple energy collection and output. The theoretical modeling and simulation results show the effectiveness of the bionic structure for ultra-low frequency vibration energy harvesting. With the influence of the coupling motion between the piezoelectric module and the electromagnetic module structure, key factors such as the excitation frequency and the number of suspended permanent magnets are investigated for their influence on the output performance of the piezoelectric module and the electromagnetic module. The experimental results indicate that the energy harvester can achieve a total output power of 321 mW when excited by a vibration signal with a frequency of 4 Hz and an amplitude of 20 mm. The experiments verified its practical value by charging the capacitor, lighting up the LED light, and powering the Mi Band-5 device.