Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

¹ Institut FEMTO-ST, CNRS, Université de Bourgogne Franche-Comté - 15B avenue des Montboucons, 25030 Besancon Cedex, France
² Division of Computer, Electrical, and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST) - Thuwal, 23955-6900, Saudi Arabia

Received: 28 October 2016
Accepted: 15 December 2016

Abstract

We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties. Our study reveals that the phenomenon of acoustically induced transparency is accompanied by an effect of near-zero density. Indeed, the dynamic effective parameters obtained from experimental data show the presence of a frequency band where the effective mass density is close to zero, with high transmission levels reaching 0.7. Furthermore, we demonstrate that such effective parameters lead to wave guiding in a 90-degrees–bent channel. This kind of acoustic metamaterial can, therefore, give rise to acoustic functions like controlling the wavefront, which may lead to very promising applications in acoustic cloacking or imaging.