Structural design and performance research of non-contact magnetic rotation-driven piezoelectric energy harvester

This paper presents a novel non-contact magnetic rotary-driven piezoelectric energy harvester (NC-MRPEH). Unlike traditional contact-driven devices, this harvester utilizes a non-contact magnetic coupling structure to achieve efficient energy conversion. The research adopts a combined approach of theoretical modeling and experimental verification to systematically investigate the effects of key parameters, such as the number and arrangement of rotating magnets, rotational speed, magnet spacing, rotational radius, number of fixed magnets, and load resistance on the output performance of the NC-MRPEH. The results show that the number of rotating magnets affects the peak power, rotational speed, and range; at low speeds, it is better to arrange the magnets in the same polarity, and at high speeds, opposite polarities are more favorable; the output power increases with the decrease in the spacing between the rotating and fixed magnets, and the influence of the rotational radius on it is less than that of the spacing, and mode 2 is negatively affected; the number of fixed magnets (when the space is fixed) and the load resistance (there is an optimal value) also have an effect. In the experiment, a single piezoelectric oscillator NC-MRPEH with specific parameters (eight rotating magnets, spacing 20 mm, radius 21 mm, mode 2, 110 kΩ resistor) successfully lit up 70 LEDs, confirming its charging efficiency and practicality.