Numerical Investigation on A Bistable Vibro-Impact Dielectric Elastomer Generator Under Low-Frequency Excitations

In order to harvest low wide bandwidth frequency vibration energy and enhance the performance of existing energy harvesters using dielectric elastomers (DEs), this paper investigates a bistable vibro-impact dielectric elastomer generator (BVI DEG), which mainly consists of a vibro-impact (VI) DEG, two identical pre-compressed springs, and a base.

First, the physical model of the BVI DEG is introduced, and its dynamical and electrical analysis models are developed. On this basis, the dynamical behaviors of the BVI DEG under a harmonic excitation are numerically investigated by bifurcation diagrams, phase trajectories and displacement time responses. Rich dynamical behaviors (such as interwell, chaotic and intrawell oscillations) of the system are revealed. Then, the energy harvesting (EH) performance under the harmonic excitation is studied for diverse parameters, including the excitation amplitude and frequency, the initial conditions of the system, the mass of the capsule, the distance between the two membranes, and the different bistable potential wells. Finally, a comparative study is conducted to demonstrate the superiority of the BVI DEG.

The system EH performance can be improved by appropriately setting various parameters, including the excitation amplitude and frequency, the initial conditions of the system, the mass of the capsule, the distance between the two membranes, and the different bistable potential wells. However, adjusting the potential barrier and the stable equilibrium position of the bistable potential well is a better way to enhance the EH performance. Moreover, the comparative study demonstrates the superiority of the BVI DEG to harvest ultra-low wide bandwidth frequency vibration energy. This work can help guide the design and optimization of the BVI DEG in the low frequency vibration environment.