Wireless Power Transfer System For A Human Motion Energy Harvester

Human motion energy harvesting as an alternative to battery powering in body worn and implanted devices is challenging during prolonged periods of inactivity. Even a buffer energy storage system will run out of power eventually if there is no external acceleration to the harvester. This paper presents a method to actuate the rotor inside a previously presented rotational piezoelectric energy harvester wirelessly via a magnetic reluctance coupling to an external driving rotor with one or more permanent magnet stacks attached. This makes it possible to recharge a battery or super-capacitor even if a patient is not moving. The use of a permanent magnet coupling has potential advantages compared to traditional inductive or ultrasonic methods, e.g. in terms of tissue damage and transmission depth. Simulation results show the achievable coupling torque for different configurations of magnet geometries and relative positions between the driving magnet stack(s) and the harvester. It is shown that using a single magnet stack yields better results than using two diametrically opposite stacks. Measurements are performed with different magnets, driving frequencies and orientations of the harvester. The results are discussed and successful energy transfer was achieved regardless Preprint submitted to Sensors And Actuators A Physical March 26, 2016 *Manuscript(includes changes marked in red font for revision documents) Click here to view linked References