Optimal potential well for maximizing performance of bi-stable energy harvester

Abstract

This letter provides an investigation on the combined influence of the potential barrier (ΔE) and separation gap of a double well (Δx) to maximize the performance of an electromagnetic bistable energy harvester (BEH). A concise method based on a high-fidelity orthogonal array sampling technique is further developed to facilitate the searching of the parameter-set corresponding to the desired potential well. According to numerical and experimental results, a barrier depth slightly lower than the threshold of interwell oscillation cooperating with a properly large separation gap is preferred for improving the power output, and enlarging the redundancy of the excitation intensity for inducing the well escape behavior. Compared to the potential well with the same barrier depth but a narrow separation gap of 1.7 mm, the optimal well with a larger Δx of 2.3 mm not only demonstrates a 60% higher output power at an acceleration of 1 g, but the intensity threshold for interwell oscillation is also reduced to 0.7 g. This work presents an insight and a method into shaping the potential well for the optimized performance and increased redundancy of a bistable configuration.