An electromagnetic vibration energy harvester using a magnet-array-based vibration-to-rotation conversion mechanism

• A vibration-to-rotation conversion mechanism using a magnet array is proposed. • The proposed motion conversion mechanism leads to high energy efficiency. • A device for harvesting low-frequency vibration energy is established. • This harvester can scavenge vibration energy from the shock absorber of a train. Using energy harvested from ubiquitous vibration for powering the increasing number of low-power electronics is a promising technique. This paper proposed an electromagnetic vibration energy harvester using an innovative vibration-to-rotation conversion mechanism based on a magnet array. A magnet vibrating along a straight path induces a torque on a rotatable cylinder fixed with an array of magnets, driving the cylinder to rotate and thus generating electricity via electromagnetic transduction. A theoretical model of the harvester was established and verified through experiments. The dynamical characteristics and optimal parameters of the harvester were investigated theoretically. Then, the optimal resistance of the external load and the capability of this harvester in energizing low-power electronics were studied. Experimental results demonstrate that the root-mean-square (RMS) power can reach a maximum value of 106.5 mW with a 300-Ω external load. Finally, an application scenario of harvesting energy from train vibration was proposed. Numerical simulation results indicate that the output power increases along with the speed of the vehicle; specifically, it can reach 50 mW when the train runs at a speed of 80 km/h. This study indicates that the proposed magnet array-based vibration energy harvester is effective in powering low-power electronics.