# 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.

## Key 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.

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Source: https://tomesphere.com/paper/1803.08655