Electromagnetic generator optimization for non-resonant energy harvester

This paper reports the modeling, optimization, and experimental results of a non-resonant electromagnetic energy harvesting system. The novelty of this paper is embedded in the use of finite element and theoretical analyses to find the optimum configuration of the generator coil. With the objective of maximizing the output power for a given magnetic structure, the coil is sized in length, thickness, and its relative positioning to magnets. Dynamic tests are also performed on first prototypes to verify theoretical calculations. As a result, 2.2 mW output power was generated at 12 Hz with vibration amplitudes as low as 1 mm. Contrary to narrow bandwidth of resonant energy harvesters, the proposed design remains operational at wide range of excitation frequency (3 - 12 Hz as tested) while requiring no tuning mechanism.