Topological wave energy harvesting in bistable lattices

Abstract

In this paper, we present an input-independent energy harvesting mechanism exploiting topological solitary waves. This class of medium transforming solitons, or transition waves, entails energy radiation in the form of trailing phonons in discrete bistable lattices. We observe numerically and experimentally that the most dominant frequencies of these phonons are invariant to the input excitations as long as transition waves are generated. The phonon energy at each unit cell is clustered around a single invariant frequency, enabling input-independent resonant harvesting with conventional energy transduction mechanisms. The presented mechanism fundamentally breaks the link between the unit cell size and the metamaterial’s operating frequencies, offering a broadband solution to energy harvesting that is particularly robust for low-frequency input sources. We further investigate the effect of lattice discreteness on the energy harvesting potential, observing two performance gaps and a topological wave harvesting pass band where the potential for energy conversion increases almost monotonically. The observed frequency-invariant phonons are intrinsic to the discrete bistable lattices, enabling broadband energy harvesting to be an inherent metamaterial property.

Subharmonic resonance and fixed-range asymptotic stability of the fractional-order SD oscillator

“…The inverse Laplace transform is performed on equation (17). The residue theorem is used to calculate the inverse Laplace transform, which can be expressed as…”

“…The strong nonlinear characteristics of the SD oscillator give this kind of system enormous advantages in converting low-frequency vibrations into electricity with high efficiency. 17,18 The sketch model of the SD oscillator is shown in Figure 1.…”

Phase patterning in multi-stable metamaterials: Transition wave stabilization and mode conversion

“…Intriguingly, analogous transformation phenomena have been elicited at the structural level from engineered media -mechanical metamaterials -comprising multi-stable elements and, likewise, have realized novel functionalities and diverse applications [6][7][8][9][10] The accessibility of the internal architecture permits a variety of metamaterial designs [11][12][13][14][15] for a tailored response; yet, with rare exception [16][17][18][19] , most designs are one-dimensional (1D) systems of identical bi-stable elements within which transition waves transform the entire structure from the (high-energy) meta-stable phase to the (low energy) ground state, demonstrating a severely limited global configuration space compared to that currently exploited in traditional phase-transforming materials.…”

Diffusive kinks turn kirigami into machines

“…As such, it mimics the slow sequential folding observed in biological systems, e.g., Mimosa Pudica. We finally demonstrate that diffusive kinks can be harnessed for basic machine-like functionalities, such as sensing, dynamic shape morphing, transport and manipulation of objects.Kinks are met across a wide range of scales in materials science, from ferro-electrics and shape-memory alloys undergoing phase transitions 1-3 to flexible metamaterials undergoing mechanical instabilities [3][4][5][6][7][8][9] . Such metamaterials are typically made of beams in series 10,11 , kirigami 12 , hinged mechanisms 13 and inflatable structures 14 .…”

“…Kinks are met across a wide range of scales in materials science, from ferro-electrics and shape-memory alloys undergoing phase transitions 1-3 to flexible metamaterials undergoing mechanical instabilities [3][4][5][6][7][8][9] . Such metamaterials are typically made of beams in series 10,11 , kirigami 12 , hinged mechanisms 13 and inflatable structures 14 .…”