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Full-Text Articles in Mechanical Engineering
Loss-Induced Enhanced Transmission In Anisotropic Density-Near-Zero Acoustic Metamaterials, Chen Shen, Yun Jing
Loss-Induced Enhanced Transmission In Anisotropic Density-Near-Zero Acoustic Metamaterials, Chen Shen, Yun Jing
Henry M. Rowan College of Engineering Faculty Scholarship
Anisotropic density-near-zero (ADNZ) acoustic metamaterials are investigated theoretically and numerically in this paper and are shown to exhibit extraordinary transmission enhancement when material loss is induced. The enhanced transmission is due to the enhanced propagating and evanescent wave modes inside the ADNZ medium thanks to the interplay of near-zero density, material loss, and high wave impedance matching in the propagation direction. The equi-frequency contour (EFC) is used to reveal whether the propagating wave mode is allowed in ADNZ metamaterials. Numerical simulations based on plate-type acoustic metamaterials with different material losses were performed to demonstrate collimation and subwavelength imaging enabled by …
Acoustic Holographic Rendering With Two-Dimensional Metamaterial-Based Passive Phased Array., Yangbo Xie, Chen Shen, Wenqi Wang, Junfei Li, Dingjie Suo, Bogdan-Ioan Popa, Yun Jing, Steven A Cummer
Acoustic Holographic Rendering With Two-Dimensional Metamaterial-Based Passive Phased Array., Yangbo Xie, Chen Shen, Wenqi Wang, Junfei Li, Dingjie Suo, Bogdan-Ioan Popa, Yun Jing, Steven A Cummer
Henry M. Rowan College of Engineering Faculty Scholarship
Acoustic holographic rendering in complete analogy with optical holography are useful for various applications, ranging from multi-focal lensing, multiplexed sensing and synthesizing three-dimensional complex sound fields. Conventional approaches rely on a large number of active transducers and phase shifting circuits. In this paper we show that by using passive metamaterials as subwavelength pixels, holographic rendering can be achieved without cumbersome circuitry and with only a single transducer, thus significantly reducing system complexity. Such metamaterial-based holograms can serve as versatile platforms for various advanced acoustic wave manipulation and signal modulation, leading to new possibilities in acoustic sensing, energy deposition and medical …