Transition Waves for Energy Trapping and Harvesting

TL;DR

This paper introduces a multistable metamaterial system that uses transition waves for simultaneous energy trapping, damping, and harvesting, with analytical, numerical, and experimental validation of its multifunctional capabilities.

Contribution

It demonstrates how transition waves in multistable metamaterials can be analytically estimated and utilized for multifunctional energy trapping, damping, and harvesting, advancing design strategies.

Findings

Transition waves enable frequency-independent energy trapping.

Multistable metamaterials outperform linear ones in damping and energy harvesting.

Energy splitting produces localized breathers that enhance damping.

Abstract

The presence of multiple stable states and associated nonlinear phenomena, such as hysteresis, in multistable mechanical metamaterials enables frequency-independent energy harvesting and shock absorption. This study focuses on shock absorption achieved by locking transition waves to trap energy at designed locations within a multistable metamaterial. We further demonstrate that the same system can simultaneously harvest energy from impact loading, thereby exhibiting multifunctionality. The model of the multistable metamaterial is a one-dimensional chain of bistable units whose transition wave dynamics are related to topological solitary waves governed by the $\phi^4$ equation. This connection enables analytical estimation of critical design parameters required for energy trapping and also the amount of energy trapped. Numerical simulations and experiments show that trapping energy in transition waves leads to enhanced damping performance compared to corresponding linear metamaterials. We further propose design variations to increase the amount of energy trapped in the transition wave. Additionally, we identify energy splitting as a damping mechanism that arises when there are repeated impulses or a single high-amplitude impulse that generates multiple transition waves. The transition waves interact to produce localized, fast-dissipating breathers, leading to a damped response. Furthermore, experiments demonstrate that multistable metamaterials can simultaneously achieve improved energy harvesting and better damping performance compared to their linear counterparts. Together, these results highlight the use of transition waves for creating multifunctional multistable metamaterials.