Frequency tunable electromagnetic vibration energy harvester based on diamagnetic levitation

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2024-02, Vol.130 (2), Article 92
• Main Authors: Zhang, Jiaxiang, Shao, Hang, Zhang, Long, Liu, Deping, Aw, Kean C., Su, Yufeng
• Format: Article
• Language: English
• Subjects: Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Diamagnetism; Dynamic characteristics; Electromagnetic induction; Energy harvesting; Frequencies; Induction coils; Levitation; Machines; Manufacturing; Materials science; Maximum power; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Thin Films; Vibration
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-07264-y

In order to solve the defect that the intrinsic frequency ω 0 of the diamagnetic levitation electromagnetic vibration energy harvester cannot be adjusted, a pulling magnet with downward attraction to the floating magnet is added below the floating magnet of the original structure. The simulation found multiple ω 0 exist in the structure with the pulling magnet, and the relationship between ω 0 and the vertical distance L L from the lifting magnet’s lower surface to the floating magnet’s upper surface is determined. It is found that ω 0 can be varied from 2.36 to 12.3 Hz by adjusting L L . The dynamic characteristics of the floating magnet is studied to obtain its amplitude-frequency curve. The output performance of the energy harvester at different ω 0 is calculated and the simulation results are well verified experimentally. The experiments show that the effective voltages can all reach their maximum after arranging the induction coil when the excitation frequency is from 2.2 to 6.1 Hz. The frequency band width for effective voltages greater than 400 mV is made up to 7.6 Hz. The maximum effective voltage of the structure with the pulling magnet is 749 mV, which is 1.98 times larger than the structure without a pulling magnet; the maximum power is 779 µW, which is 7.9 times larger than the structure without a pulling magnet. Experiments show that the structure with the pulling magnet not only significantly broadens the effective bandwidth of the energy harvester, but also significantly improves the output performance of the energy harvester. In addition, the nonlinear characteristics of the system make it possible to obtain good output performance even when the vibration frequency is far from ω 0 .