Arbitrary Shaped Acoustic Concentrators Enabled by Nihility Media

Based on the transformation acoustics (TA) methodology, an innovative approach for designing arbitrary shape concentrators is proposed. unlike previous works, which utilized inhomogenous and anisotropic materials to localize the incident waves in an arbitrary domain, the same functionality will be attained by introducing only one homogenous anisotropic medium, which is called acoustic nihility media (ANM). A great advantage of this method is that the attained materials are not dependent on the shape of the concentrator. That is regardless of the device geometry, a constant ANM will be used for each new shape and the output results do not alter. This will circumvent the conventional transformation acoustics' sophisticated and tedious calculations and could be easily implemented in real life scenarios.