Footstep Energy Harvesting with the Magnetostrictive Fiber Integrated Shoes

Wearable energy harvesting devices attract attention as the devices provide electrical power without inhibiting user mobility and independence. While the piezoelectric materials integrated shoes have been considered as wearable energy harvesting devices for a long time, they can lose their energy harvesting performance after being used several times due to their brittleness. In this study, we focused on Fe-Co magnetostrictive materials and fabricated Fe-Co magnetostrictive fiber integrated shoes. We revealed that Fe-Co magnetostrictive fiber integrated shoes are capable of generating 1.2 µJ from 1000 steps of usual walking by the Villari (inverse magnetostrictive) effect. It seems that the output energy is dependent on user habit on ambulation, not on their weight. From both a mechanical and functional point of view, Fe-Co magnetostrictive fiber integrated shoes demonstrated stable energy harvesting performance after being used many times. It is likely that Fe-Co magnetostrictive fiber integrated shoes are available as sustainable and wearable energy harvesting devices.