Dual-mode electromagnetic energy harvester by Halbach arrays

Cost-effective electromagnetic energy harvesting is a sustainable energy technology that enables solutions for future microsensor power supply. Enhancements in the power density of the electromagnetic energy harvester (EMEH) have always been a challenge. To conquer the energy-insufficiency issue of a single energy harvester, hybrid energy harvesting technology is becoming an emerging consensus. Based on Halbach electromagnetic array, this paper proposes a dual-mode EMEH, which can effectively harvest energies in both vibration and rotation modes. The parameter optimization of the Halbach electromagnetic array was carried out to enhance the magnetic field intensity according to different arrangements and structural parameters. And then the experimental investigation was implemented to validate the power supply capabilities of low-power consumption microsensors. The experimental results demonstrate that: the maximum output power could reach 100.1 mW in vibration mode, while in rotation working conditions, the maximum output power equals 3.86 W. The application scenario for powering the monitoring devices in rail transit is validated by the railway spectra vibration tests, indicating a novel and implementable solution for the energy supply of IoT-based microgrids for future green and sustainable transportation.