Maximizing Electromagnetic Energy Harvester Efficiency Through Optimized Magnetic Configurations for Wireless Sensor Networks †

Wireless and battery-less sensor nodes are pivotal in the future of technology, particularly for continuous monitoring and minimizing maintenance costs. These nodes are especially critical in large-scale agricultural systems, where they enable tasks such as detection, identification, and fertilization, so it is important that self-powered wireless sensors operate reliably. This paper presented an electromagnetic generator within a novel energy harvester to investigate how the power density and efficiency can be improved by optimizing the magnet arrangement and orientation. Four designs are proposed with different magnet orientations and an iron steel plate for flux concentrating. The finite element magnetic method (FEMM) is mainly used to simulate the fine-tuning of the magnet arrangement combined with MATLAB and some mathematical methods to find a suitable magnet arrangement. The results show that, by increasing the number of magnets to nine, adding a pure iron wall, and using a Halbach array, the magnetic flux density can be increased by 1.92 times.