title: Sound pressure level gain in an acoustic metamaterial cavity.
abstract: The inherent attenuation of a homogeneous viscous medium limits radiation propagation, thereby restricting the use of many high-frequency acoustic devices to only short-range applications. Here, we design and experimentally demonstrate an acoustic metamaterial localization cavity which is used for sound pressure level (SPL) gain using double coiled up space like structures thereby increasing the range of detection. This unique behavior occurs within a subwavelength cavity that is 1/10(th) of the wavelength of the incident acoustic wave, which provides up to a 13 dB SPL gain. We show that the amplification results from the Fabry-Perot resonance of the cavity, which has a simultaneously high effective refractive index and effective impedance. We also experimentally verify the SPL amplification in an underwater environment at higher frequencies using a sample with an identical unit cell size. The versatile scalability of the design shows promising applications in many areas, especially in acoustic imaging and underwater communication.
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Daejeon, 305-343, Korea.
authors.forename: Kyungjun
authors.initials: K
authors.lastname: Song
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Yuseong-Gu, Daejeon, 305-701, Korea.
authors.forename: Kiwon
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Daejeon, 305-343, Korea.
authors.forename: Shin
authors.initials: S
authors.lastname: Hur
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Daejeon, 305-343, Korea.
authors.forename: Jun-Hyuk
authors.initials: JH
authors.lastname: Kwak
authors.affiliation: Signal Processing Laboratory, Department of Information and Communication Engineering, Pukyong National University, 45 Yongso-ro, Nam-Gu, Busan, 608-737, Korea.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Park
authors.affiliation: Signal Processing Laboratory, Department of Information and Communication Engineering, Pukyong National University, 45 Yongso-ro, Nam-Gu, Busan, 608-737, Korea.
authors.forename: Jong Rak
authors.initials: JR
authors.lastname: Yoon
authors.affiliation: Department of Mechanical Engineering, Pukyong National University, 365 Sinsun-Ro, Nam-Gu, Busan, 608-739, Korea.
authors.forename: Jedo
authors.initials: J
authors.lastname: Kim