Impacts of stopper type and material on the broadband characteristics and performance of energy harvesters

Abstract

Exploiting nonlinear impact force induced by a stopper has been widely proposed to broaden the bandwidth of energy harvesters from mechanical vibrations, but the previous studies just directly employed the stopper and did not consider the effect of inherent factors of the stopper like its type and material. This letter devotes to efficiently utilize the stopper to broaden the resonance region of the energy harvester mainly from perspective of stopper type and material. Four stopper types are taken into account including the stopper with rigid and soft materials and the spring stopper. Experimental results show that two sides followed stopper type can greatly increase the bandwidth which is much better than other considered types. Importantly, using the stopper with soft materials or the spring stopper is followed by a wider resonance region and a higher output voltage of the energy harvester compared to that with rigid materials. Moreover, agreements between theoretical predictions and experimental measurements indicate the feasibility of using the trilinear spring model to describe the nonlinear impact force which is determined by stopper type and material. The present study delivers to essentially improve the output performance of energy harvesters by selecting the efficient stopper.

Autonomous Resonance‐Tuning Mechanism for Environmental Adaptive Energy Harvesting

“…The impact force of the clamp plays an essential role in the increased power despite the shorter active length. [ 32 ]…”

“…The impact force of the clamp plays an essential role in the increased power despite the shorter active length. [32] To evaluate the resonance-frequency tuning time of the ART energy harvester, a thin polyvinylidene fluoride (PVDF) piezoelectric layer (20 μm) was attached to TB #1 (Figure 4e), and the voltage signals from the PVDF and MB were precisely monitored during the ART operation of adaptive clamp #1. As shown in Figure 4f, the TB voltage exhibited a peak when the vibration frequency reached 42 Hz and then stabilized.…”

Nonlinear Dynamics and Characterization of Beam-Based Systems with Contact/Impact Boundaries

“…Adding stoppers to a system results in hardening effects that increase the bandwidth of the resonant frequency range, which is ideal for energy harvesting purposes. In another paper, Zhou et al [4] studied a similar energy harvesting system considering the effects of rigid and soft stoppers; soft stoppers were found to have an increased output voltage and larger frequency bandwidth making them most ideal for energy harvesting purposes. To address a wide range of contact/impact problems, the experimental system described in this work is designed with the ability to be reconstructed into infinite configurations.…”

Insights on the Bifurcation Behavior of a Freeplay System with Piecewise and Continuous Representations

“…Vibro-contact and vibro-impact dynamical systems are very common across engineering fields, with examples ranging from large aeroelastic structures [1] to small energy harvesters [2]. Various numerical methods and models have been used and developed to represent contact/impact behavior.…”

“…Other representations that are continuous and fully smooth have been developed, which may be based on combinations of absolute value and polynomial functions [2,4], the hyperbolic tangent function [1,5], or similar functions/combinations. These continuous contact-force representations allow for low computational costs and remove the accumulating roundoff error, but there are trade-offs with other sources of error.…”