Design, evaluation, and application of a multi-magnetic circuit electromagnetic vibration energy harvester with a narrow air gap structure

This study proposes a novel electromagnetic vibration energy harvester (EMVEH) with multiple magnetic circuits that reduce the air gap width to less than 1 mm by introducing magnetic yokes. The design utilizes the opposing changes in the overlap state between the beam and two yokes, causing the magnetic flux of the coil to alternate between positive and negative directions, thereby improving power generation efficiency. We optimized the magnet size, magnetic yoke height, and yoke spacing. The output characteristics of the EMVEH were assessed using vibration experiments, and its power-generation capability for moving vehicles was evaluated. Additionally, we verified the feasibility of a self-powered Internet of Things (IoT) system utilizing the EMVEH by integrating an energy management circuit. This EMVEH offers a sustainable energy solution for IoT systems by harvesting otherwise wasted industrial vibrations, reducing dependency on batteries, lowering maintenance costs, and mitigating environmental impacts by eliminating battery disposal issues.