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Zhao SD, Zhang NL, Han P, Gu Y, Dong HW. Enhanced Broadband Manipulation of Acoustic Vortex Beams Using 3-bit Coding Metasurfaces through Topological Optimization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2308349. [PMID: 38229570 DOI: 10.1002/smll.202308349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/14/2023] [Indexed: 01/18/2024]
Abstract
The acoustic coding metasurfaces (ACMs) have the ability to manipulate complex acoustic behavior by reconstructing the coding sequence. In particular, the design of broadband coding enhances the versatility of ACMs. ACMs offer significant advantages over traditional metasurfaces, including a limited number of units and flexible wave control performance. The unit quantity is determined by 2n, with 1-bit utilizing 2 units, 2-bit using 4 units, and 3-bit employing 8 units. Utilizing multiple bits allows for precise control over the phase of sound waves and enables the realization of more intricate acoustic functions. To address the requirements of broadband multi-bit applications, this paper presents the development of novel 3-bit broadband reflected acoustic coding metasurfaces (BACMs) with eight coding units. These metasurfaces are systematically designed using the bottom-up topology optimization method. A constant phase difference of 45° can be achieved across all eight coding units within a broad frequency range. Additionally, the spiral distribution of phase differences enables the construction of an acoustic vortex metasurface. Moreover, by combining the convolution method, the strategies are outlined for constructing vortex-focusing metasurfaces and vortex beam manipulation metasurfaces. These 3-bit coding metasurfaces possess significant potential in the fields of acoustic particle suspension and acoustic communication.
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Affiliation(s)
- Sheng-Dong Zhao
- School of Mathematics and Statistics, Qingdao University, Qingdao, 266071, P. R. China
- Institute of Mechanics for Multifunctional Materials and Structures, Qingdao University, Qingdao, 266071, P. R. China
| | - Na-Li Zhang
- School of Mathematics and Statistics, Qingdao University, Qingdao, 266071, P. R. China
| | - Ping Han
- School of Mathematics and Statistics, Qingdao University, Qingdao, 266071, P. R. China
| | - Yan Gu
- School of Mathematics and Statistics, Qingdao University, Qingdao, 266071, P. R. China
- Institute of Mechanics for Multifunctional Materials and Structures, Qingdao University, Qingdao, 266071, P. R. China
| | - Hao-Wen Dong
- Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing, 100081, China
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2
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Palma G, Iemma U. A metacontinuum model for phase gradient metasurfaces. Sci Rep 2023; 13:13038. [PMID: 37563187 PMCID: PMC10415379 DOI: 10.1038/s41598-023-39956-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/02/2023] [Indexed: 08/12/2023] Open
Abstract
Acoustic metamaterials and metasurfaces often present complex geometries and microstructures. The development of models of reduced complexity is fundamental to alleviate the computational cost of their analysis and derivation of optimal designs. The main objective of this paper is the derivation and validation of a metacontinuum model for phase gradient-based metasurfaces. The method is based on the transformation acoustics framework and defines the metasurface in terms of anisotropic inertia and bulk modulus. Thermal and viscous dissipation effects in the metacontinuum are accounted for by introducing a complex-valued speed of sound. The model is implemented in a commercial FEM code, and its predictions are compared with numerical simulations on the original geometry and also using an equivalent boundary impedance approach. The results are examined for an exterior acoustics benchmark and for an in-duct installation in terms of transmission coefficient with the four-pole matrix method. The metacontinuum model gives solid results for the prediction of the acoustic properties of the examined metasurface samples for all the analyzed configurations, as accurate as the equivalent impedance model on which it is based and outperforming it in some circumstances.
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Affiliation(s)
- Giorgio Palma
- Department of Civil, Computer Science and Aeronautical Technologies Engineering, Roma Tre University, 00146, Rome, Italy.
| | - Umberto Iemma
- Department of Civil, Computer Science and Aeronautical Technologies Engineering, Roma Tre University, 00146, Rome, Italy
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3
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Stein M, Keller S, Luo Y, Ilic O. Shaping contactless radiation forces through anomalous acoustic scattering. Nat Commun 2022; 13:6533. [PMID: 36319654 PMCID: PMC9626492 DOI: 10.1038/s41467-022-34207-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
Waves impart momentum and exert force on obstacles in their path. The transfer of wave momentum is a fundamental mechanism for contactless manipulation, yet the rules of conventional scattering intrinsically limit the radiation force based on the shape and the size of the manipulated object. Here, we show that this intrinsic limit can be broken for acoustic waves with subwavelength-structured surfaces (metasurfaces), where the force becomes controllable by the arrangement of surface features, independent of the object's overall shape and size. Harnessing such anomalous metasurface scattering, we demonstrate complex actuation phenomena: self-guidance, where a metasurface object is autonomously guided by an acoustic wave, and tractor beaming, where a metasurface object is pulled by the wave. Our results show that bringing the metasurface physics of acoustic waves, and its full arsenal of tools, to the domain of mechanical manipulation opens new frontiers in contactless actuation and enables diverse actuation mechanisms that are beyond the limits of traditional wave-matter interactions.
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Affiliation(s)
- Matthew Stein
- grid.17635.360000000419368657Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | - Sam Keller
- grid.17635.360000000419368657Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | - Yujie Luo
- grid.17635.360000000419368657Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | - Ognjen Ilic
- grid.17635.360000000419368657Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
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4
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Ultra-Broadband Bending Beam and Bottle Beam Based on Acoustic Metamaterials. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12063025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We report the realization of an ultra-broadband bending beam based on acoustic metamaterials by the theoretical prediction and the numerical validation. The proposed structure is composed of a series of straight tubes with spatially modulated depths. We analytically derive the depth profile required for the generation of an ultra-broadband bending beam, and examine the performance of the metastructure numerically. The design is then extended for the generation of a three-dimensional bottle beam. The transverse trapping behaviours on small rigid objects by the bottle beam are investigated based on the force potential. Our work will help the further study of broadband acoustic meta-structures, and may also find applications in a variety of fields such as ultrasound imaging, health monitoring and particle manipulations.
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Janus acoustic metascreen with nonreciprocal and reconfigurable phase modulations. Nat Commun 2021; 12:7089. [PMID: 34873154 PMCID: PMC8648919 DOI: 10.1038/s41467-021-27403-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022] Open
Abstract
Integrating different reliable functionalities in metastructures and metasurfaces has become of remarkable importance to create innovative multifunctional compact acoustic, optic or mechanical metadevices. In particular, implementing different wave manipulations in one unique material platform opens an appealing route for developing integrated metamaterials. Here, the concept of Janus acoustic metascreen is proposed and demonstrated, producing two-faced and independent wavefront manipulations for two opposite incidences. The feature of two-faced sound modulations requires nonreciprocal phase modulating elements. An acoustic resonant unit cell with rotating inner core, which produces a bias by a circulating fluid, is designed to achieve high nonreciprocity, leading to decoupled phase modulations for both forward and backward directions. In addition, the designed unit cell consisting of tunable phase modulators is reconfigurable. A series of Janus acoustic metascreens including optional combinations of extraordinary refraction, acoustic focusing, sound absorption, acoustic diffusion, and beam splitting are demonstrated through numerical simulations and experiments, showing their great potential for acoustic wavefront manipulation. Here, the authors introduce the concept of Janus acoustic metascreen for independent wavefront manipulations for two opposite incidences. They use acoustic circulators with rotating inner cores to achieve high nonreciprocity, and demonstrate tunable combinations of wavefront manipulations.
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6
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Research Progress and Development Trends of Acoustic Metamaterials. Molecules 2021; 26:molecules26134018. [PMID: 34209353 PMCID: PMC8271960 DOI: 10.3390/molecules26134018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 11/21/2022] Open
Abstract
Acoustic metamaterials are materials with artificially designed structures, which have characteristics that surpass the behavior of natural materials, such as negative refraction, anomalous Doppler effect, plane focusing, etc. This article mainly introduces and summarizes the related research progress of acoustic metamaterials in the past two decades, focusing on meta-atomic acoustic metamaterials, metamolecular acoustic metamaterials, meta-atomic clusters and metamolecule cluster acoustic metamaterials. Finally, the research overview and development trend of acoustic metasurfaces are briefly introduced.
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7
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Nonlocal elastic metasurfaces: Enabling broadband wave control via intentional nonlocality. Proc Natl Acad Sci U S A 2020; 117:26099-26108. [PMID: 33020274 DOI: 10.1073/pnas.2004753117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While elastic metasurfaces offer a remarkable and very effective approach to the subwavelength control of stress waves, their use in practical applications is severely hindered by intrinsically narrow band performance. In applications to electromagnetic and photonic metamaterials, some success in extending the operating dynamic range was obtained by using nonlocality. However, while electronic properties in natural materials can show significant nonlocal effects, even at the macroscales, in mechanics, nonlocality is a higher-order effect that becomes appreciable only at the microscales. This study introduces the concept of intentional nonlocality as a fundamental mechanism to design passive elastic metasurfaces capable of an exceptionally broadband operating range. The nonlocal behavior is achieved by exploiting nonlocal forces, conceptually akin to long-range interactions in nonlocal material microstructures, between subsets of resonant unit cells forming the metasurface. These long-range forces are obtained via carefully crafted flexible elements, whose specific geometry and local dynamics are designed to create remarkably complex transfer functions between multiple units. The resulting nonlocal coupling forces enable achieving phase-gradient profiles that are functions of the wavenumber of the incident wave. The identification of relevant design parameters and the assessment of their impact on performance are explored via a combination of semianalytical and numerical models. The nonlocal metasurface concept is tested, both numerically and experimentally, by embedding a total-internal-reflection design in a thin-plate waveguide. Results confirm the feasibility of the intentionally nonlocal design concept and its ability to achieve a fully passive and broadband wave control.
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8
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Polychronopoulos S, Memoli G. Acoustic levitation with optimized reflective metamaterials. Sci Rep 2020; 10:4254. [PMID: 32144310 PMCID: PMC7060201 DOI: 10.1038/s41598-020-60978-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 02/17/2020] [Indexed: 11/09/2022] Open
Abstract
The simplest and most commonly used acoustic levitator is comprised of a transmitter and an opposing reflecting surface. This type of device, however, is only able to levitate objects along one direction, at distances multiple of half of a wavelength. In this work, we show how a customised reflective acoustic metamaterial enables the levitation of multiple particles, not necessarily on a line and with arbitrary mutual distances, starting with a generic input wave. We establish a heuristic optimisation technique for the design of the metamaterial, where the local height of the surface is used to introduce delay patterns to the reflected signals. Our method stands for any type and number of sources, spatial resolution of the metamaterial and system's variables (i.e. source position, phase and amplitude, metamaterial's geometry, relative position of the levitation points, etc.). Finally, we explore how the strength of multiple levitation points changes with their relative distance, demonstrating sub-wavelength field control over levitating polystyrene beads into various configurations.
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Affiliation(s)
- Spyros Polychronopoulos
- University of Sussex, School of Engineering and Informatics, Brighton, BN1 5EL, United Kingdom. .,National and Kapodistrian University of Athens, Department of Informatics and Telecommunications, Athens, Greece.
| | - Gianluca Memoli
- University of Sussex, School of Engineering and Informatics, Brighton, BN1 5EL, United Kingdom.
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9
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Acoustic waveguide with virtual soft boundary based on metamaterials. Sci Rep 2020; 10:981. [PMID: 31969667 PMCID: PMC6976684 DOI: 10.1038/s41598-020-57986-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/03/2020] [Indexed: 11/09/2022] Open
Abstract
The use of acoustic metamaterials with novel phenomena to design acoustic waveguides with special properties has obvious potential application value. Here, we propose a virtual soft boundary (VSB) model with high reflectivity and half cycle phase loss, which consists of an acoustic propagation layer and an acoustic metamaterial layer with tube arrays. Then the waveguide designed by the VSB is presented, and the numerical and experimental results show that it can separate acoustic waves at different frequencies without affecting the continuity and the flow of the medium in the space. The VSB waveguide can enrich the functions of acoustic waveguides and provide more application prospects.
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10
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Mellish S, Taherzadeh S, Attenborough K. Approximate impedance models for point-to-point sound propagation over acoustically-hard ground containing rectangular grooves. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:74. [PMID: 32007012 DOI: 10.1121/10.0000490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
A modal model for diffraction by a contiguous array of rectangular grooves in an acoustically-hard plane is extended to predict the free space acoustic field from a point source above such a structure. Subsequently, an approximate effective impedance model for grooved surfaces is presented. Measurements have shown that these ground surfaces can be used for outdoor noise reduction but accurate modelling has required the use of computationally expensive numerical methods. The extended modal model and approximate impedance model inspired by it yield equivalent results in a fraction of the time taken by the boundary element method, for example, and could be used when designing grooved surfaces to reduce noise from road traffic.
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Affiliation(s)
- Steve Mellish
- Faculty of STEM, The Open University, Milton Keynes, MK7 6AA, United Kingdom
| | - Shahram Taherzadeh
- Faculty of STEM, The Open University, Milton Keynes, MK7 6AA, United Kingdom
| | - Keith Attenborough
- Faculty of STEM, The Open University, Milton Keynes, MK7 6AA, United Kingdom
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11
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Melnikov A, Chiang YK, Quan L, Oberst S, Alù A, Marburg S, Powell D. Acoustic meta-atom with experimentally verified maximum Willis coupling. Nat Commun 2019. [PMID: 31316062 DOI: 10.1103/physrevapplied.13.064067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
Acoustic metamaterials are structures with exotic acoustic properties, with promising applications in acoustic beam steering, focusing, impedance matching, absorption and isolation. Recent work has shown that the efficiency of many acoustic metamaterials can be enhanced by controlling an additional parameter known as Willis coupling, which is analogous to bianisotropy in electromagnetic metamaterials. The magnitude of Willis coupling in a passive acoustic meta-atom has been shown theoretically to have an upper limit, however the feasibility of reaching this limit has not been experimentally investigated. Here we introduce a meta-atom with Willis coupling which closely approaches this theoretical limit, that is much simpler and less prone to thermo-viscous losses than previously reported structures. We perform two-dimensional experiments to measure the strong Willis coupling, supported by numerical calculations. Our meta-atom geometry is readily modeled analytically, enabling the strength of Willis coupling and its peak frequency to be easily controlled.
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Affiliation(s)
- Anton Melnikov
- Vibroacoustics of Vehicles and Machines, Technical University of Munich, Garching b. Munich, 85748, Germany.
- SBS Bühnentechnik GmbH, Dresden, 01259, Germany.
- Centre for Audio, Acoustics and Vibration University of Technology Sydney, Sydney, NSW, 2007, Australia.
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2612, Australia.
| | - Yan Kei Chiang
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2612, Australia
| | - Li Quan
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Sebastian Oberst
- Centre for Audio, Acoustics and Vibration University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Andrea Alù
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
- Photonics Initiative, Advanced Science Research Center City University of New York, New York, NY, 10031, USA
| | - Steffen Marburg
- Vibroacoustics of Vehicles and Machines, Technical University of Munich, Garching b. Munich, 85748, Germany
| | - David Powell
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2612, Australia.
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12
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Li Y, Ren Z, Yuan X, Chen M, Cao W, Cheng Q, Jin Z, Cheng X, Zhang C, Yang J, Fang D. Reflection phase dispersion editing generates wideband invisible acoustic Huygens's metasurface. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:166. [PMID: 31370652 DOI: 10.1121/1.5116012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/17/2019] [Indexed: 06/10/2023]
Abstract
Acoustic metasurfaces show non-traditional abilities in wave manipulation and provide alternate mechanisms for information communication and invisibility technology. However, most of the mechanisms remain narrow band (relative bandwidth ∼5%), and a wideband trait is essential for engineering applications. For example, controllable effective material properties-reflection or transmission phase-has barely been realized in wideband because the intrinsic dispersion relation is not always editable. In this paper, wideband reflection phase editing is realized, and wideband invisibility of a phase preserved Huygens's metasurface on a flat background is achieved with anomalous reflection. This metasurface is built with proposed unsymmetrical twin Helmholtz resonators which reach a predefined dispersion relation target value. The total instantaneous acoustic fields show nearly identical carpeting effects in a consecutive band with relative bandwidth 52.1% (from 5400 to 9200 Hz) in simulation and experiment.
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Affiliation(s)
- Ying Li
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Zhiwen Ren
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Xujin Yuan
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Mingji Chen
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Wenkang Cao
- School of Information Science and Engineering, Southeast University, Nanjing 210096, China
| | - Qiang Cheng
- School of Information Science and Engineering, Southeast University, Nanjing 210096, China
| | - Zhongkun Jin
- Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaodong Cheng
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Cheng Zhang
- School of Information Science and Engineering, Southeast University, Nanjing 210096, China
| | - Jun Yang
- Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
| | - Daining Fang
- Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures, Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China
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13
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Ma F, Xu Y, Wu JH. Shell-type acoustic metasurface and arc-shape carpet cloak. Sci Rep 2019; 9:8076. [PMID: 31147607 PMCID: PMC6542823 DOI: 10.1038/s41598-019-44619-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 05/16/2019] [Indexed: 11/16/2022] Open
Abstract
We systematically propose a thin shell-type acoustic metasurface, which could be used to design a carpet cloak that closely covers an arc-shaped object, therefore providing the necessary support for hiding an object with any arbitrary shape. To facilitate the experimental measurement, however, the work here starts with some rotary spherical shell-type and ellipsoidal shell-type cell structures. The measured and calculated sound transmission loss (STL) results of these structures suggest that the sound insulation performances of the shell-type structure are quite different from those of the plate-type structure, indicating a possible break in the shape of the classical sound insulation curve. Considering also that cylindrical shell structures are more widely used in practice than the rotary shell structures, a number of two-dimensional bilayer cylindrical and elliptic cylindrical shell structures were, therefore, designed in this assay. Due to the asymmetry of the structure, the shell-type cells could exhibit bianisotropic sound absorption, reflection and effective parameters. Furthermore, the stiffness of the thin shell structure changed nonlinearly with the changing of the radius of curvature, with a wing shape tendency. In addition, a bilayer cylindrical shell-type acoustic metasurface and an arc-shaped carpet acoustic cloak were successively designed, wherein the phased compensation of differently shaped cell structures could be adjusted by means of a new engineering iso-phase design method. This work could provide the necessary guidance to extend existing results in the field of membrane- and plate-type acoustic metamaterials for shell-type structures, and the realization of the arc-shaped cloak could provide support for the design of a carpet acoustical cloak for use with arbitrary shapes.
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Affiliation(s)
- Fuyin Ma
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 71009, China.
| | - Yicai Xu
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 71009, China
| | - Jiu Hui Wu
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 71009, China
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14
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Beadle JG, Hooper IR, Sambles JR, Hibbins AP. Broadband, slow sound on a glide-symmetric meander-channel surface. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:3190. [PMID: 31153334 DOI: 10.1121/1.5109549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
The acoustic surface waves supported by hard surfaces patterned with repeat-period, meandering grooves are explored. The single, continuous groove forms a glide-symmetric surface, inhibiting the formation of a bandgap at the first Brillouin-zone boundary. Consequently, the acoustic surface waves exhibit an almost constant, sub-speed-of-sound, group velocity over a broad frequency band. Such slow, broadband modes may have applications in controlling the flow of noise over surfaces.
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Affiliation(s)
- J G Beadle
- Electromagnetic and Acoustic Materials Group, Department of Physics and Astronomy, Physics Building, Stocker Road, University of Exeter, Exeter, EX4 4QL, United Kingdom
| | - I R Hooper
- Electromagnetic and Acoustic Materials Group, Department of Physics and Astronomy, Physics Building, Stocker Road, University of Exeter, Exeter, EX4 4QL, United Kingdom
| | - J R Sambles
- Electromagnetic and Acoustic Materials Group, Department of Physics and Astronomy, Physics Building, Stocker Road, University of Exeter, Exeter, EX4 4QL, United Kingdom
| | - A P Hibbins
- Electromagnetic and Acoustic Materials Group, Department of Physics and Astronomy, Physics Building, Stocker Road, University of Exeter, Exeter, EX4 4QL, United Kingdom
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15
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Ultra-Broadband Acoustic Diode in Open Bend Tunnel by Negative Reflective Metasurface. Sci Rep 2018; 8:16089. [PMID: 30382127 PMCID: PMC6208409 DOI: 10.1038/s41598-018-34314-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 10/15/2018] [Indexed: 11/17/2022] Open
Abstract
We theoretically and numerically propose an open bend tunnel with the capability of realizing ultra-broadband unidirectional transmission. The designed tunnel can isolate acoustic wave incidence from opposite directions and substance like the fluids or objects can exchange freely by employing acoustic gradient metasurface. The underlying mechanism is due to apparent negative reflection in ultra-broadband frequency range when the incoming angle impinging on the metasurface is over the critical incidence. The numerical results keep a good agreement with the theoretical analyses. The proposed design could be employed to generate various situations, like broadband noise control, architectural acoustics and ultrasound imaging.
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16
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Zhai S, Song K, Ding C, Wang Y, Dong Y, Zhao X. Tunable Acoustic Metasurface with High-Q Spectrum Splitting. MATERIALS 2018; 11:ma11101976. [PMID: 30322182 PMCID: PMC6213771 DOI: 10.3390/ma11101976] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 11/25/2022]
Abstract
We propose a tunable acoustic metasurface using a nested structure as the microunit, which is constituted by two distinct resonators. Thanks to the coupling resonance for the microunit and by simply adjusting the rotation angle of the inner split cavity, this nested structure provides nearly 2π phase shift. The full-wave simulations demonstrate that the constructed metasurface can be tuned to reflect incident sound waves to different directions in the operation frequency region with a very narrow bandwidth, which is a key functionality for many applications such as filtering and imaging. Meanwhile, the reflected sound waves out of the operation frequency region always remain unchanged. As a result, a high Q-factor spectrum splitting can be realised. The presented metasurface is of importance to develop many metamaterial-based devices, such as tunable acoustic cloaks and acoustic switching devices.
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Affiliation(s)
- Shilong Zhai
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
| | - Kun Song
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
| | - Changlin Ding
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
| | - Yuanbo Wang
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
| | - Yibao Dong
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
| | - Xiaopeng Zhao
- Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University (NWPU), Xi'an 710129, China.
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17
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Wavefront manipulation based on transmissive acoustic metasurface with membrane-type hybrid structure. Sci Rep 2018; 8:14171. [PMID: 30242248 PMCID: PMC6155023 DOI: 10.1038/s41598-018-32547-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/10/2018] [Indexed: 12/02/2022] Open
Abstract
We designed and demonstrated a gradient acoustic metasurface to manipulate the transmissive wavefront. The gradient metasurface is composed of eight elements based on membrane-type hybrid structures, whose thickness and width are about 1/5 and 1/20 of the incident wavelength, respectively. Here, we employ acoustic theory to analyze the transmission spectrum and phase gradient of the metasurface, the properties of high transmission efficiency and discrete phase shifts over the full \documentclass[12pt]{minimal}
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\begin{document}$$2\pi $$\end{document}2π range can be achieved simultaneously. By appropriate selection of the phase profile along the transverse coordinate of the metasurface or the angle of incident wave, the transmissive wavefront manipulations based on metasurface can be obtained as expected from the generalized Snell’s law, such as anomalous refraction, acoustic cloak based on flat focusing, acoustic self-bending beam, conversion of propagating wave to surface wave and negative refraction. Our gradient metasurface may have potential application in low-loss acoustic devices.
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Tang Y, Zhu Y, Liang B, Yang J, Yang J, Cheng J. One-way Acoustic Beam Splitter. Sci Rep 2018; 8:13573. [PMID: 30206365 PMCID: PMC6134148 DOI: 10.1038/s41598-018-29579-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/13/2018] [Indexed: 11/16/2022] Open
Abstract
As a key component of various acoustic systems, acoustic beam splitter (BS) finds important application in many scenarios, yet are conventionally based on the assumption that the acoustic waves propagate as easily when incident from either input or output side. It would therefore be intriguing, from the viewpoints of both science and technology, to break through this limit by realizing acoustic BSs supporting asymmetric transmission. Here we propose the concept of one-way acoustic BS capable of splitting acoustic beam incident from the input port into multiple beams while effectively reducing the backward transmission from any of the output ports. Furthermore, our design enables flexibly adjusting the number and angle of output beams by blocking the unused line defects. The numerical results verify the theoretical predictions and demonstrate the phenomenon of one-way acoustic BS at the predesigned frequency. Our design with functionality and flexibility bridges the gap between acoustic diodes and BSs and may enable novel multi-functional devices with great application prospects in diverse fields such as acoustic integrated circuits and acoustic communication.
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Affiliation(s)
- Yifan Tang
- Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| | - Yifan Zhu
- Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| | - Bin Liang
- Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China.
| | - Jing Yang
- Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| | - Jun Yang
- Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jianchun Cheng
- Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
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Fine manipulation of sound via lossy metamaterials with independent and arbitrary reflection amplitude and phase. Nat Commun 2018; 9:1632. [PMID: 29691413 PMCID: PMC5915438 DOI: 10.1038/s41467-018-04103-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 04/04/2018] [Indexed: 11/08/2022] Open
Abstract
The fine manipulation of sound fields is critical in acoustics yet is restricted by the coupled amplitude and phase modulations in existing wave-steering metamaterials. Commonly, unavoidable losses make it difficult to control coupling, thereby limiting device performance. Here we show the possibility of tailoring the loss in metamaterials to realize fine control of sound in three-dimensional (3D) space. Quantitative studies on the parameter dependence of reflection amplitude and phase identify quasi-decoupled points in the structural parameter space, allowing arbitrary amplitude-phase combinations for reflected sound. We further demonstrate the significance of our approach for sound manipulation by producing self-bending beams, multifocal focusing, and a single-plane two-dimensional hologram, as well as a multi-plane 3D hologram with quality better than the previous phase-controlled approach. Our work provides a route for harnessing sound via engineering the loss, enabling promising device applications in acoustics and related fields.
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Ma F, Huang M, Xu Y, Wu JH. Bilayer synergetic coupling double negative acoustic metasurface and cloak. Sci Rep 2018; 8:5906. [PMID: 29651157 PMCID: PMC5897382 DOI: 10.1038/s41598-018-24231-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 03/29/2018] [Indexed: 11/18/2022] Open
Abstract
In this paper, we propose a bilayer plate-type lightweight double negative metasurface based on a new synergetic coupling design concept, by which the perfect absorption, double negative bands, free manipulation of phase shifts with a 2π span and acoustic cloak can be successively realized. Firstly, the synergetic behavior between resonant and anti-resonant plates is presented to construct a bilayer unit in which each component respectively provides a pre-defined function in realizing the perfect absorption. Based on this bilayer structure, a double negative band with simultaneously negative effective mass density and bulk modulus is obtained, which, as a metasurface, can obtain continuous phase shifts almost completely covering a 2π range, thus facilitating the design of a three-dimensional (3D) acoustic cloak. In addition, based on this strong sound absorption concept, a two-dimensional (2D) omnidirectional broadband acoustical dark skin, covering between 800 to 6000 Hz, is also demonstrated through the proposed bilayer plate-type structure form. The proposed design concepts and metasurfaces have widespread potential application values in strong sound attenuation, filtering, superlens, imaging, cloak, and extraordinary wave steering, in which the attributes of strong absorption, double negative parameters or continuous phase shifts with full 2π span are required to realize the expected extraordinary physical features.
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Affiliation(s)
- Fuyin Ma
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Meng Huang
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, 100081, China
| | - Yicai Xu
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jiu Hui Wu
- School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 710049, China
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21
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Wang X, Mao D, Li Y. Broadband acoustic skin cloak based on spiral metasurfaces. Sci Rep 2017; 7:11604. [PMID: 28912441 PMCID: PMC5599615 DOI: 10.1038/s41598-017-11846-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/31/2017] [Indexed: 11/09/2022] Open
Abstract
A skin cloak based on the acoustic metasurface made of graded spiral units is proposed and numerically investigated. The presented skin cloak is an acoustical layer consisting of 80 subwavelength-sized unit cells, which provide precise local phase modulation and hence resort the disturbed sound filed in such a way to hide the object to acoustic wave. Numerical simulations show that the suggested skin cloak both work well under normal and small-angled incidences. By taking the advantage of the spiral-typed metasurface, the suggested skin cloak is rather thin with thickness in the order around 1/7 of the wavelength of target frequency, moreover, the intrinsic characteristics of modest dispersion ensure the skin cloak provides remarkable acoustic invisibility in a broad frequency ranging from 2500 Hz to 3600 Hz.
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Affiliation(s)
- Xu Wang
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
| | - Dongxing Mao
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
| | - Yong Li
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China. .,Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
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Lan J, Li Y, Xu Y, Liu X. Manipulation of acoustic wavefront by gradient metasurface based on Helmholtz Resonators. Sci Rep 2017; 7:10587. [PMID: 28878264 PMCID: PMC5587551 DOI: 10.1038/s41598-017-10781-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/14/2017] [Indexed: 11/16/2022] Open
Abstract
We designed a gradient acoustic metasurface to manipulate acoustic wavefront freely. The broad bandwidth and high efficiency transmission are achieved by the acoustic metasurface which is constructed with a series of unit cells to provide desired discrete acoustic velocity distribution. Each unit cell is composed of a decorated metal plate with four periodically arrayed Helmholtz resonators (HRs) and a single slit. The design employs a gradient velocity to redirect refracted wave and the impedance matching between the metasurface and the background medium can be realized by adjusting the slit width of unit cell. The theoretical and numerical results show that some excellent wavefront manipulations are demonstrated by anomalous refraction, non-diffracting Bessel beam, sub-wavelength flat focusing, and effective tunable acoustic negative refraction. Our designed structure may offer potential applications for the imaging system, beam steering and acoustic lens.
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Affiliation(s)
- Jun Lan
- College of Computer Science and Technology, Nanjing Tech University, Nanjing, 211800, P. R. China
| | - Yifeng Li
- College of Computer Science and Technology, Nanjing Tech University, Nanjing, 211800, P. R. China.
- Key Laboratory of Modern Acoustics, Ministry of Education, Nanjing University, Nanjing, 210093, P. R. China.
| | - Yue Xu
- College of Computer Science and Technology, Nanjing Tech University, Nanjing, 211800, P. R. China
| | - Xiaozhou Liu
- Key Laboratory of Modern Acoustics, Ministry of Education, Institute of Acoustics and School of Physics, Nanjing University, Nanjing, 210093, P. R. China
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23
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Sound Insulation in a Hollow Pipe with Subwavelength Thickness. Sci Rep 2017; 7:44106. [PMID: 28272486 PMCID: PMC5341061 DOI: 10.1038/srep44106] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/01/2017] [Indexed: 11/08/2022] Open
Abstract
Suppression of the transmission of undesired sound in ducts is a fundamental issue with wide applications in a great variety of scenarios. Yet the conventional ways of duct noise control have to rely on mismatched impedance or viscous dissipation, leading the ducts to have ventilation capability weakened by inserted absorbers or a thick shell to accommodate bulky resonators. Here we present a mechanism for insulating sound transmission in a hollow pipe with subwavelength thickness, by directly reversing its propagating direction via anomalous reflection at the flat inner boundary with well-designed phase profile. A metamaterial-based implementation is demonstrated both in simulation and in experiment, verifying the theoretical prediction on high-efficient sound insulation at the desired frequencies by the resulting device, which has a shell as thin as 1/8 wavelength and an entirely open passage that maintains the continuity of the background medium. We have also investigated the potential of our scheme to work in broadband by simply cascading different metamaterial unit cells. Without the defects of blocked path and bulky size of existing sound insulators, we envision our design will open new route to sound insulation in ducts and have deep implication in practical applications such as designs of ventilation fans and vehicle silencers.
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Xie B, Tang K, Cheng H, Liu Z, Chen S, Tian J. Coding Acoustic Metasurfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603507. [PMID: 27921327 DOI: 10.1002/adma.201603507] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 09/30/2016] [Indexed: 06/06/2023]
Abstract
Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.
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Affiliation(s)
- Boyang Xie
- The MOE Key Laboratory of Weak Light Nonlinear Photonics, School of Physics, TEDA Institute of Applied Physics, and the 2011 Project Collaborative Innovation Center for Biological Therapy, Nankai University, Tianjin, 300071, China
| | - Kun Tang
- School of Physics and Technology and Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Hua Cheng
- The MOE Key Laboratory of Weak Light Nonlinear Photonics, School of Physics, TEDA Institute of Applied Physics, and the 2011 Project Collaborative Innovation Center for Biological Therapy, Nankai University, Tianjin, 300071, China
| | - Zhengyou Liu
- School of Physics and Technology and Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Shuqi Chen
- The MOE Key Laboratory of Weak Light Nonlinear Photonics, School of Physics, TEDA Institute of Applied Physics, and the 2011 Project Collaborative Innovation Center for Biological Therapy, Nankai University, Tianjin, 300071, China
| | - Jianguo Tian
- The MOE Key Laboratory of Weak Light Nonlinear Photonics, School of Physics, TEDA Institute of Applied Physics, and the 2011 Project Collaborative Innovation Center for Biological Therapy, Nankai University, Tianjin, 300071, China
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Zhu H, Semperlotti F. Anomalous Refraction of Acoustic Guided Waves in Solids with Geometrically Tapered Metasurfaces. PHYSICAL REVIEW LETTERS 2016; 117:034302. [PMID: 27472114 DOI: 10.1103/physrevlett.117.034302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 05/14/2023]
Abstract
The concept of a metasurface opens new exciting directions to engineer the refraction properties in both optical and acoustic media. Metasurfaces are typically designed by assembling arrays of subwavelength anisotropic scatterers able to mold incoming wave fronts in rather unconventional ways. The concept of a metasurface was pioneered in photonics and later extended to acoustics while its application to the propagation of elastic waves in solids is still relatively unexplored. We investigate the design of acoustic metasurfaces to control elastic guided waves in thin-walled structural elements. These engineered discontinuities enable the anomalous refraction of guided wave modes according to the generalized Snell's law. The metasurfaces are made out of locally resonant toruslike tapers enabling an accurate phase shift of the incoming wave, which ultimately affects the refraction properties. We show that anomalous refraction can be achieved on transmitted antisymmetric modes (A_{0}) either when using a symmetric (S_{0}) or antisymmetric (A_{0}) incident wave, the former clearly involving mode conversion. The same metasurface design also allows achieving structure embedded planar focal lenses and phase masks for nonparaxial propagation.
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Affiliation(s)
- Hongfei Zhu
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Fabio Semperlotti
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Ray W. Herrick Laboratories, School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
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26
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Wang X, Wang X, Yu W, Jiang Z, Mao D. Acoustic performance of boundaries having constant phase gradient. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:EL7. [PMID: 27475215 DOI: 10.1121/1.4954754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this paper, inhomogeneous boundaries having constant phase gradient are investigated. In principle, such a theoretically proposed boundary is dispersionless. In practice, however, when the boundary is realized by a subwavelength-structured tubes array, the impedance discretization brings about sub-reflections at high frequencies. Moreover, determined by the longest duct in the array, a realized boundary is impractically thick. Therefore, a finite-thickness boundary is further proposed by truncating and periodizing the tubes in the array. In this paper, the theoretical analysis agrees well with the numerical simulations. By appropriately choosing its phase gradient and target frequency, the finite-thickness boundaries have potential applications in noise control.
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Affiliation(s)
- Xu Wang
- Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China
| | - Xiaonan Wang
- Shanghai Academy of Environmental Sciences, No. 508 Qingzhou Road, Shanghai 200233, China , , , ,
| | - Wuzhou Yu
- Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China
| | - Zaixiu Jiang
- Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China
| | - Dongxing Mao
- Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China
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