A broadband bistable energy harvester with self-decreasing potential barrier effect: Design, modeling and experiments

The conventional bistable energy harvester (CBEH) is difficult to break through the potential barrier for largeamplitude inter-well motion under weak excitation environments, which results in a narrow effective bandwidth. This paper proposes a bistable energy harvester with self-decreasing potential barrier effect (BEH-DPBE) for harvesting low-frequency vibrational energy. A spring is introduced to transform the fixed end of the S-type power generating beam into a movable end, while its oscillator has a dual function of dynamically reducing the potential barrier in the return trip and enhancing the potential energy in the outward trip. The characteristics of the proposed energy harvester are evaluated and analyzed by combining finite element simulations, numerical studies, and experiments. Finally, the effects of key parameters, such as the spring pre-compression, proof mass, and load resistance, are studied. In low-frequency conditions, the effective bandwidth and peak-to-peak voltage of BEH-DPBE are 6.35 Hz (5.98-12.33 Hz) and 10.1 V, respectively. The proposed BEH-DPBE can effectively capture energy in low-frequency ambient vibrations.