Design and experiment of magnetostrictive-electromagnetic hybrid floor vibration energy harvester

This paper proposes using a magnetostrictive-electromagnetic hybrid floor vibration energy harvester (MEHH), which employs the Villari effect and Faraday's Law of Electromagnetic Induction. This harvester can generate three output voltages simultaneously when subjected to the same vibration source, and it can supply power to multiple microelectronic devices simultaneously, thereby enhancing the efficiency of vibrational energy harvesting. The magnetostrictive component (MH) utilizes a rod-shaped Terfenol-D as the core element. A two-stage force amplification mechanism has been incorporated to amplify and process the input force generated by the vibration source and apply it to both ends of the Terfenol-D rod to enhance energy conversion efficiency. An optimization analysis of the primary mechanism's dimensions was conducted to determine the final optimized dimensions and obtain a force magnification of 24.01. The electromagnetic section (EH) has a permanent magnet as the core element, and the central mover, which consists of the permanent magnet, floats up and down in the axial direction inside the hollow tube. The flux density generated by different forms of central movers is simulated and studied to determine the optimal arrangement of the central movers. During the experiment, the MEHH was excited by 240 N, the peak voltage of MH output reached 2.66 V, and the maximum power generated by the matched load resistor reached 334 mW. The peak voltage of EH output reached 1.59 V, and the maximum power generated by the matched load resistor reached 45.1 mW.