Acoustic insulation and directional refraction of dual-functional pentamode metasurface.

Acoustic metasurface is a membrane-like two-dimensional metamaterial with subwavelength thickness and special acoustic properties. Based on generalized Snell's laws, acoustic metasurface produce a series of unconventional acoustic phenomena including anomalous refraction/reflection. This paper proposes a dual-functional acoustic metasurface composed of asymmetric pentamode units with directional refraction and acoustic isolation. The numerical shows that the acoustic insulation and vibration attenuation can be obtained from 7.0 kHz to 8.4 kHz, while efficient directional transmission can be achieved between 2.0 kHz and 4.0 kHz. This study may provide a pathway for acoustic metasurface to control the acoustic propagation in diodes, insulators and cloaks. [ABSTRACT FROM AUTHOR]