Extraordinary Sound Transmission through Density-Near-Zero Ultranarrow Channels

TL;DR

This paper demonstrates a new method for extraordinary sound transmission through ultranarrow channels using zero-density metamaterials, enabling applications like sensing and cloaking.

Contribution

It introduces the concept of acoustic supercoupling with zero-density metamaterials and proposes a practical realization using transverse membranes.

Findings

Achieved anomalous sound transmission through ultranarrow channels.

Proved a novel acoustic tunneling mechanism based on impedance matching.

Envisioned applications in sensing, noise control, cloaking, and energy harvesting.

Abstract

We introduce the acoustic equivalent of 'supercoupling' by studying the anomalous sound transmission and uniform energy squeezing through ultranarrow acoustic channels filled with zero-density metamaterials. We propose their realization by inserting transverse membranes with a subwavelength period along the channel, and we prove a novel form of acoustic tunneling based on impedance matching and infinite phase velocity at the zero-density operation. We envision applications in sensing, noise control, cloaking and energy harvesting.