High power density vibration energy harvester with high permeability magnetic material

An alternative design of vibration energy harvester was demonstrated to significantly increase the output power density. This design had two magnetic solenoids fixed at two sides of a spring supported hard magnet pair with anti-parallel magnetization, which produced a spatially inhomogeneous bias magnetic field for switching the flux inside the solenoids during vibration. Experimental results showed an output voltage of 2.52 V and a power density 20.84 mWcm³ at 42 Hz, with a half peak working bandwidth of 6 Hz. This vibration energy harvester design leads to high output voltage, power and power density that are critical for real applications.