Tunable fluid-solid metamaterials for manipulation of elastic wave propagation in broad frequency range

TL;DR

This paper introduces a novel tunable fluid-solid metamaterial inspired by biological systems, enabling broad-range control of elastic wave propagation through liquid distribution adjustments, surpassing traditional stiffness tuning methods.

Contribution

It presents a new fluid-solid composite metamaterial with tunable band gaps and effective mass density, demonstrated via theory, simulation, and experiments, for broad-frequency wave manipulation.

Findings

Tunable band gaps achieved by controlling liquid distribution.

Effective mass density can be adjusted at high frequencies.

Broad frequency range manipulation of elastic waves demonstrated.

Abstract

Current strategies for designing tunable locally resonant metamaterials are based on tuning the stiffness of the resonator; however, this approach presents a major shortcoming as the effective mass density is constant at high frequency. Here, this paper reports a type of tunable locally elastic metamaterial-'called tunable fluid-solid composite'-inspired by the functions of heart and vessels in animals and humans. The proposed metamaterial consists of several liquid or gas inclusions in a solid matrix, controlled through a pair of embedded pumps. Both the band gap and effective mass density at high frequency can be tuned by controlling the liquid distribution in the unit cell, as demonstrated through a combination of theoretical analysis, numerical simulation, and experimental testing. Finally, we show that the tunable fluid-solid metamaterial can be utilized to manipulate wave propagation over a broad frequency range, providing new avenues for vibration isolation and wave guiding.