Multi-Degree-of-Freedom Energy Harvesting Device with Time-Varying Potential Energy and Adjustable Characteristics

The nonlinear force generated by the magnetic device facilitates the width of the effective operating range of the system and thus provides a promising approach for designing self-powered sensing devices. However, existing energy harvesting devices still fall short in terms of efficiency and adjustability. This paper addresses the challenges by introducing the concepts of compactness and tunability, combined with nonlinear characteristics, multiple degrees of freedom, and time-varying potential energy. A multi-stable dual-beam nonlinear energy harvesting device featuring magnetic coupling and dual piezoelectric transducers is proposed. As a key performance indicator, the induced voltage RMS value quantitatively characterizes energy conversion effectiveness, while system stability and harvesting efficiency are comparatively analyzed across varying frequency ratios and potential energy configurations. The topological configuration of basins of attraction is computationally analyzed under static potential energy conditions, providing phase-space visualization of the system’s dynamic stability characteristics. The numerical results show that the ratio of frequencies of the system and the initial position of the magnet will directly affect the potential energy form. The combination of the two degrees of freedom of the piezoelectric beam and the mode of the trolley drive would be critical to the stability and energy harvesting performance of the device.