A study of an electromagnetic energy harvester using multi-pole magnet

This paper presents an electromagnetic energy harvester (EMEH) based on multi-pole magnet to harvest energy from ambient vibrations. The EMEH consists of a cylindrical housing made of acrylic glass, a copper coil, and NdFeB (N35) permanent magnets. The physical modeling of the EMEH has been demonstrated through a series of mathematical equations. MATLAB program has been used to calculate the open circuit voltages for different magnets. The finite element analysis (FEA) has been adopted to examine the magnetic field area and flux lines of the magnet encompassing the coil. The fabricated EMEH using 3 magnets can generate up to 4.84 mW with normalized power density (NPD) of 2.14 × 103 μW/g2 cm3 at a resonance frequency of 6 Hz against a load resistance of 1.0 kΩ.