Simulation and testing of a micro electromagnetic energy harvester for self-powered system

This paper describes a low cost and efficient electromagnetic vibration energy harvester (EVEH) for a self-powered system. The EVEH consists of a resistant (copper) spring, a permanent magnet (NdFeB35) and a wire-wound copper coil. The copper spring was fabricated by the laser precision cutting technology. A numerical model was adopted to analyze magnetic field distribution of a rectangle permanent magnet. The finite element (FEM) soft ANSYS was used to simulate the mechanical properties of the system. The testing results show that the micro electromagnetic vibration energy harvester can generate the maximal power 205.38 μW at a resonance frequency of 124.2 Hz with an acceleration of 0.5 g (g = 9.8 ms−2) across a load the 265 Ω and a superior normalized power density (NPD) of 456.5 μW cm−3 g−2. The magnetic field distribution of the permanent magnet was calculated to optimize geometric parameters of the coil. The proposed EVEH has a high efficiency with the lower cost.