Ultrathin ultralight acoustic cloak

Existing designs of transformation acoustic cloaks are not easy to implement in many practical situations because of their large dimensions, while scattering cancellation cloaks do not protect the inner cloak volume. Here we report implementation of an acoustic metamaterial exhibiting cylindrical dispersion in an ultra-thin (~1mm) and ultra-lightweight (~3g) acoustic cloak design intended to protect a human-head-size object in air, which combines scattering cancellation in the far-field with efficient sound proofing of the inner cloak volume.