Frequency-selective asymmetric transmission via the lossy acoustic metasurface

Asymmetric acoustic transmission (AAT) has been demonstrated using diverse acoustic metasurfaces (AMs). Here, we show that an emerging class of lossy AMs enables frequency-selective AAT. The asymmetric and symmetric transmissions can be realized at interested operating frequencies in specific incident angle ranges. The underlying mechanism is attributed to the inherent loss inside the labyrinthine structure of different arrangements. Our design introduces the freedom degree of frequency control for the achievement of the AAT devices. (C) 2019 The Japan Society of Applied Physics