# Aerogel-based metasurfaces for perfect acoustic energy absorption

## TL;DR

This paper introduces a novel acoustic metasurface using aerogel plates that achieves perfect sound absorption through impedance matching, combining theoretical, numerical, and experimental approaches.

## Contribution

It presents a new design of subwavelength perfect sound absorbers using aerogel-based metasurfaces with a comprehensive analysis method.

## Key findings

- Achieved perfect sound absorption with aerogel metasurfaces.
- Demonstrated impedance matching using Argand diagram analysis.
- Validated the design through experiments and simulations.

## Abstract

The unusual viscoelastic properties of silica aerogel plates are efficiently used to design subwavelength perfect sound absorbers. We theoretically, numerically and experimentally report a perfect absorbing metamaterial panel made of periodically arranged resonant building blocks consisting of a slit loaded by a clamped aerogel plate backed by a closed cavity. The impedance matching condition is analyzed using the Argand diagram of the reflection coefficient, i.e., the trajectory of the reflection coefficient as a function of frequency in the complex plane. The lack or excess of losses in the system can be identified via this Argand diagram in order to achieve the impedance matching condition. The universality of this tool can be further exploited to design more complex metasurfaces for perfect sound absorption, thus allowing the rapid design of novel and efficient absorbing metamaterials.