Design and experimental study of a bistable magnetoelectric vibration energy harvester with nonlinear magnetic force scavenging structure

A bistable magnetoelectric vibration energy harvester using nonlinear magnetic force is proposed. It consists of a planar spring, a magnetoelectric transducer with an annular magnetic circuit, and a coil assembly with a ferrite bobbin inside. Based on these, a nonlinear magnetic force between the ferrite bobbin and permanent magnet arrays can be generated when the relative displacement changes, which can broaden the operating frequency bandwidth of the harvester. The nonlinear magnetic force makes the harvester demonstrate some special dynamic behaviors including the inter-well and chaotic motions, which are performed by the finite element analysis. And, the experimental validations are also carried to verify the performance of the proposed harvester. The results show that the output power can reach 10 mW in a relatively wide operating frequency range with a 90 Omega resistance load under 1 g harmonic excitation. In addition, a real vehicle road's vibration signals from a highway bridge are acquired to estimate the practical energy harvesting performance of the harvester. The results show that the RMS output voltage and load power of the harvester can reach 3.16 V and 110.95 mW under 10x road spectrum excitations, respectively.