magnetostriction, energy harvest, galfenol, permanent magnet
Manually-pushed carts with rotating wheels are easily seen around us. Also, active RFID has been gaining ground toward commercial usage. Currently possible power supply may be a rechargeable or disposable battery for the reader. The proposed idea is to harvest electricity from the rotating wheels, and to operate the reader with the harvested electricity. Thus, this study presents the feasibility of a wheel-based energy harvester harnessing a Galfenol cantilever wound coil and permanent magnets (PMs). Simulation is used to obtain proper PM array design. The experimental harvester consists of a coil-wound Galfenol cantilever with a PM onto the end of the beam, a core with PM array on its surfaces, and two wheels. Galfenol cantilever has a dimension of 100x15x3mm3, and wound coils are 660 turns of 0.45-mm diameter wire. The bias magnet is NdFeB37 with a thickness of 15mm. For the experiments, the core is rotated by using an electric motor. The inverse magnetostrictive effect causes a decrease or an increase of the flux due to the applied compressive or tensile stress, resulting in generating electricity. The average V and A are estimated to be ±1.65V and ±350mA. It is enough electricity to turn several LED on .