Theoretical and experimental study of an electromagnetic vibration energy harvester

In this paper, we propose a vibration energy harvester which can convert mechanical vibration energy into electrical energy using diamagnetic levitation technology and electromagnetic induction. The energy harvester is mainly composed of permanent magnets, pyrolytic graphite sheets and copper coils that are electroplated on the pyrolytic graphite sheets. Finite element analysis is adopted to study the levitation space and output voltage of the energy harvester in COMSOL Multiphyscis (TM) 5.3. The key factors of the maximum stable levitation space of the floating magnet are determined, and parameters which determine the output voltage of the harvester are investigated in detail. Under an external excitation with 5 Hz frequency and 0.8mm amplitude, the maximum output voltage and the maximum power of a single 80-turn coil are 1.64 mV and 0.0755 mu W, respectively. In addition, the optimization method for the output voltage of the energy harvester is also discussed. Frictionless movement of the floating magnet is beneficial to improve the energy harvesting efficiency. The energy harvesting setup is potential in the power supply of wireless sensors network and autonomous micro devices.