title: Broadband Acoustic Hyperbolic Metamaterial.
abstract: In this Letter, we report on the design and experimental characterization of a broadband acoustic hyperbolic metamaterial. The proposed metamaterial consists of multiple arrays of clamped thin plates facing the y direction and is shown to yield opposite signs of effective density in the x and y directions below a certain cutoff frequency, therefore, yielding a hyperbolic dispersion. Partial focusing and subwavelength imaging are experimentally demonstrated at frequencies between 1.0 and 2.5 kHz. The proposed metamaterial could open up new possibilities for acoustic wave manipulation and may find usage in medical imaging and nondestructive testing.
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Yangbo
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Ni
authors.initials: N
authors.lastname: Sui
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Wenqi
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Cummer
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Jing