Mechanical Wave Propagation within Nanogold Granular Crystals

TL;DR

This study uses molecular dynamics simulations to explore wave propagation in nanogold granular crystals, revealing unique localized solitary waves and tunable transmittance, with implications for nanoscale mechanical wave control.

Contribution

It introduces a validated nonlinear spring contact model for gold nanospheres and demonstrates their potential as nanoscale mechanical wave tuners.

Findings

Homogeneous lattices support localized solitary waves at 300 K.

Diatomic lattices allow tuning of wave transmittance and speed.

The nonlinear model captures complex nanoscale interactions.

Abstract

We computationally investigate the wave propagation characteristics of nanoscopic granular crystals composed of one-dimensionally arrayed gold nanoparticles using molecular dynamics simulation. We examine two basic configurations, i.e. homogeneous lattices and diatomic lattices with mass-mismatch. We discover that homogeneous lattices of gold nanospheres support weakly dissipative and highly localized solitary wave at 300 K, while diatomic lattices have a good tuning ability of transmittance and wave speed. We establish a validated nonlinear spring contact model with the consideration of complex interactions between gold nanospheres which reveals the physical nature of wave behaviors at nanoscale. This work sheds light on the application of nanogold as a novel mechanical wave tuner, qualitatively and fundamentally different from its counterpart granular materials at meso- and macroscale.