Design and Experiment of Magnetostrictive Knee Joint Kinetic Energy Harvester

Energy harvesting technologies offer a novel solution for powering portable and wearable electronics. This paper presents a knee‐joint kinetic energy harvester based on a magnetostrictive Fe–Ga alloy, designed to scavenge energy from human motion. The harvester consists of a crank‐slider mechanism, a bent composite beam, an Fe–Ga alloy sheet, a pickup coil, and a biased magnetic field. During walking, the crank‐slider mechanism drives the beam to deflect, inducing cyclic deformation in the Fe–Ga alloy. Through the Villari effect and Faraday's law of electromagnetic induction, mechanical energy is converted into electrical energy. The energy conversion efficiency is enhanced by optimizing coil parameters, bias field configuration, and external load. Experimental results demonstrate that when worn at the knee joint during jogging at 7 km/h, the harvester delivers a stable output power of 14.96–15.65 mW, sufficient to power low‐energy electronics. Real‐world application tests confirm its stable performance and practical potential. This Fe–Ga‐based harvester exhibits promising prospects for human motion energy harvesting, providing a feasible power solution for future wearable devices.