A novel magnetically coupled bistable electromagnetic energy harvester for human movement energy harvesting

Abstract In recent years, self-powered technologies for low-power electronic devices have garnered significant attention. Numerous nonlinear electromagnetic harvesters have been employed to harvest environmental vibrational energy to power electronic devices. However, most nonlinear electromagnetic energy harvesters rely on external magnets to achieve bistability, which constrains their miniaturization. In this paper, a novel magnetically coupled bistable electromagnetic energy harvester (MCB-EEH) is developed, which consists primarily of fixed magnets, a moving magnet, a ring-shaped steel sheet, coils, and a slide rail. The nonlinear interaction between the ring-shaped steel sheet and the moving magnet imparts bistable characteristics to the harvester, thereby eliminating the demand for external magnets and facilitating a compact design. The electromechanical coupled dynamics model of the MCB-EEH is derived. The output performance of the MCB-EEH is evaluated through numerical simulation and experiments. The results indicate that the frequency bandwidth of the MCB-EEH ranges from 5 Hz to 10 Hz under an excitation amplitude of 1 g. The average power of the MCB-EEH can reach 24.3 mW during moving backpack energy harvesting at a human speed of 9 km h −1 . Frequency sweep experiments and human motion energy harvesting tests confirm that MCB-EEH is capable of powering LEDs and other portable electronic devices.