Harvesting Vibration Energy and Wind Energy by a Bi-stable Harvester: Modeling and Experiments

In realistic environments, there often appears the concurrence of base excitation and blowing wind. Harvesting both vibration energy and wind energy by an unique harvester is attractive. In this paper, we proposed a harvester integrating bi-stability and galloping to realize this aim. The nonlinear dynamical model of the bistable energy harvester under concurrent wind and base excitations is established. The galloping effects on the responses are explored based on the established model, for both harmonic and random excitations. The corresponding experiments are conducted to validate the theoretical prediction. The experimental results are consistent with the simulation results. At a wind speed of U=2 m/s, the bandwidth of large-amplitude inter-well motion of the bi-stable energy harvester is extended by about 18.5%. The critical random excitation level for snap-through is reduced by 58% and the total output voltage at random excitation is increased by 53.4%. Thus, the harvester could scavenge the wind and vibration energies at a high efficiency. These conclusions could be helpful for improving the harvesting efficiency in the real environment.