A Magnetic Softening Resonator With Flat Power Generation for Nonlinear Vibration Energy Harvesting

This paper describes the design of a softening magnetic resonator with wide and flat power-frequency characteristics for nonlinear vibration energy harvesting. The softening characteristics of the resonator are implemented by a magnetic spring designed by solving the arrangement problem of a single moving magnet that serves as a mass and many small fixed magnets using Lasso regression to approach the ideal equivalent spring stiffness. In this study, the effect of the dimensions of the moving magnet is particularly addressed. The results suggest that the optimization of the height of the moving magnet is necessary because it is dominant in the scale of the restoring force variation of the magnetic spring.