Architected lattices for simultaneous broadband attenuation of airborne sound and mechanical vibrations in all directions

TL;DR

This paper introduces a novel 3D architected lattice that effectively attenuates both airborne sound and mechanical vibrations across all directions and polarizations, advancing the control of wave propagation in materials.

Contribution

It presents the first load-bearing, single-material 3D lattice capable of broadband attenuation of both acoustic and elastic waves in all directions.

Findings

Successfully demonstrated broadband attenuation in experiments.

Achieved simultaneous control of acoustic and elastic wave propagation.

Developed a new design methodology for multi-modal wave attenuation.

Abstract

Phononic crystals and acoustic metamaterials are architected lattices designed to control the propagation of acoustic or elastic waves. In these materials, the dispersion properties and the energy transfer are controlled by selecting the lattices' geometry and their constitutive material properties. Most designs, however, only affect one mode of energy propagation, transmitted either as acoustic, airborne sound or as elastic, structural vibrations. Here, we present a design methodology to attenuate both acoustic and elastic waves simultaneously in all polarizations. We experimentally realize the first three-dimensional, load bearing, architected lattice, composed of a single-material, that responds in a broadband frequency range in all directions.