Variable-Flux Biaxial Vibration Energy Harvester

Variable-flux biaxial vibration energy harvesting (VBH) is a novel architecture for electromagnetic vibrations energy harvesting. In this paper, we present VBH prototypes for low-frequency (<;10 Hz) and low-amplitude vibrations energy harvesting. The transduction mechanism uses stationary magnetic circuit, a coil, and a moving ferromagnetic ball. The ferromagnetic ball disrupts the magnetic field and induces a voltage in the coil. We analyzed the performance of the VBH experimentally, and the results exhibited the efficient operation of the system in harvesting energy at center frequencies as low as 6.5 Hz with harvesting bandwidth as wide as 5.8 Hz and an output power of 154 μW.