Analysis of a Magnetostrictive Harvester with a Fully Coupled Nonlinear FEM Modeling

A force-driven kinetic energy harvester, designed to be excited with impulse-like mechanical loads, is presented. Energy harvesting is a promising technique to feed wireless sensor networks. The proposed device exploits three rods of Galfenol and has been modeled through FEM COMSOL Multiphysics with nonlinear fully coupled characteristics. They consider the general behaviors of magnetostrictive materials and are compatible with thermodynamics. The preliminary results of the time-domain simulations, with an impulse-like force applied, have been compared with experimental results showing a good agreement. Moreover, the proposed nonlinear modeling has shown better performances with respect to software built-in magnetostrictive models. At the same time, further modeling improvements seem to be needed in the future to better fit the harmonic content of the free evolution of the device.