Characteristics Study and Floating Magnet Structure Improvement of Airflow Energy Harvester Based on Diamagnetic Levitation

In this paper, an airflow energy harvester based on diamagnetic levitation is investigated to optimize the floating magnet configuration for enhanced energy conversion and harvesting performance. The influence of the notch radius of the floating magnet on its rotational characteristics is analyzed through simulation, leading to an improved structural design with the floating magnet encapsulated by a resin housing. Comparative simulation and experiment are conducted on the airflow energy harvester before and after the improvements. The results demonstrate that the corresponding steady‐state levitation gap at the same upper spacing increases. The housing does not affect the energy conversion coefficient, and both the rotational speed of the combined floating magnet and the induced electromotive force (EMF) generated in the coils increase as the housing's external notch radius decreases. At an airflow rate of 3000 sccm through both nozzles, the improved harvester yields an average peak voltage of 3.463 V, an effective voltage of 2.449 V, and an average harvested power of 237.94 mW without an external circuit. The optimal output power is 112 mW, with a power density of 1.2556 mW/cm 3 , and an energy conversion efficiency of 28.96%. 60 LEDs are illuminated by the improved energy harvester, verifying its application feasibility.