Bandwidth enhancement of a gimbaled-pendulum vibration energy harvester using spatial multi-stable mechanism

Abstract

Vibration energy harvesting based on pendulums is a promising approach for low-frequency excitation and large-scale application. Conventional design is to match the natural frequency of the pendulum energy harvester to the excitation frequency, which results in a narrow bandwidth. This work develops a gimbaled-pendulum energy harvester with spatial multi-stability by using a magnetic mechanism. The structure, modeling, design consideration, and dynamic simulation of the energy harvester are presented in detail with the aid of numerical analysis. Comparative experiments such as motion patterns, electrical outputs with variable excitations, load effect, and bidirectional excitation are implemented based on a fabricated prototype to evaluate the proposed design. It is shown that the energy harvester is prone to enter into high-energy orbits even at low excitation frequency and amplitude due to the effect of multi-well potential distribution. In general, the bandwidth of the energy harvester is significantly enhanced through its spatial multi-stability. This work can provide a candidate for low-frequency vibration energy harvesting with wide spectrum excitation.