Magnetostrictive wires-epoxy resin composite structures for human motion energy harvesting

Abstract

Encapsulation of magnetostrictive alloy wires in epoxy resin has great potential for energy harvesting and can be applied to energy harvesting in human motion. In this work, a magnetostrictive wire-epoxy resin arch composite structure was proposed for harvesting energy generated by foot motion. A prestress was introduced during the resin curing process, and the relationship between the output voltage and material properties was derived based on the Villari effect. Three kinds of Fe-based magnetostrictive wires were prepared and their magnetic properties were measured, then a prototype single-layer arch composite structure was fabricated and an experimental platform was built for testing, and the amplitude of the output open-circuit voltage could reach 936 mV under an impact pressure of 750 N, which proved that the Fe–Ga alloy composite structure was superior to Fe–Co and Fe–Ni alloys in energy harvesting. The double-layer arch-shaped Fe–Ga composite structures energy harvesting prototype outputs a maximum voltage of up to 940 mV in foot energy harvesting experiments, and collected a maximum power of up to 2.45 mW at a step frequency of 3.5 Hz. Consequently, this work emphasized the feasibility of magnetostrictive alloy-epoxy composite structures for energy harvesting in human motion and the potential for developing new ways of energy harvesting.