SM01.06.03 : Acoustic Manipulation with Soft Material-Based Parabolic Reflectors

4:15 PM–4:30 PM Apr 4, 2018 (America - Denver)

PCC West, 100 Level, Room 104 AB

Saurabh Apte1 Eric Ni1 Yanjun Wang1 Jingjin Xie1 Xiyue Zou1 Tongfen Liang1 Robert Froster1 Aaron Mazzeo1

1, Rutgers University, Piscataway, New Jersey, United States

This presentation will describe a unique parabolic acoustic reflector with an inflatable structure, which has tunable gain and directivity. Conventional parabolic reflectors focus and amplify sound waves using metallic or plastic dishes with fixed geometries. This work aims to create a morphable reflecting surface that deforms into a concave structure to provide directional amplification of incoming acoustic waves. The deformable concave structure is a silicone elastomer (Ecoflex 00-10) that has a measured reflection coefficient of approximately 0.9 at frequencies ranging from 500 Hz to 5000 Hz. This reflective coefficient suggests these silicone-based elastomers are capable of serving as reflective substrates for advanced morphable devices to manipulate sound. For parabolic reflectors, acoustic gain and directionality depend on the level of vacuum applied to the elastomeric membranes, which affects the curvature of the paraboloid. Experiments performed in closed and open environments, along with simulations, demonstrate that the soft reflecting surface is capable of transformation into a set of desired parabolic shapes between an initial planar geometry (neutral position) and configurations with varying curvature. This type of system might find future uses for adjustable parabolic microphones and long-range communication devices.