Sub-wavelength phononic crystal liquid sensor

AbstractPractically applied techniques for ultrasonic biomedical imaging employ delay-and-sum (DAS) beamforming which can resolve two objects down to 2.1λ within the acoustic Fresnel zone. Here, we demonstrate a phononic metamaterial lens (ML) for detection of laterally subwavelength object features in tissue-like phantoms beyond the phononic crystal evanescent zone and Fresnel zone of the emitter. The ML produces metamaterial collimation that spreads 8x less than the emitting transducer. Utilizing collimation, 3.6x greater lateral resolution beyond the Fresnel zone limit was achieved. Both hard objects and tissue approximating masses were examined in gelatin tissue phantoms near the Fresnel zone limit. Lateral dimensions and separation were resolved down to 0.50λ for hard objects, with tissue approximating masses slightly higher at 0.73λ. The work represents the application of a metamaterial for spatial characterization, and subwavelength resolution in a biosystem beyond the Fresnel zone limit.

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Ultrafast Rayleigh-like streaming in a sub-wavelength slit between two phononic crystal plates

Journal of Applied Physics ◽

10.1063/1.5058206 ◽

2019 ◽

Vol 125 (13) ◽

pp. 134903 ◽

Cited By ~ 2

Author(s):

Fei Li ◽

Xiangxiang Xia ◽

Zhiting Deng ◽

Junjun Lei ◽

Yaxi Shen ◽

...

Keyword(s):

Phononic Crystal ◽

Sub Wavelength

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the Interaction of Resonance And Bragg Scattering Effects for the Locally Resonant Phononic Crystal with Alternating Elastic and Fluid Matrices

Archives of Acoustics ◽

10.1515/aoa-2017-0075 ◽

2017 ◽

Vol 42 (4) ◽

pp. 725-733 ◽

Cited By ~ 4

Author(s):

Bo Yuan ◽

Yong Chen ◽

Min Jiang ◽

Shuai Tang ◽

Miao He ◽

...

Keyword(s):

Phononic Crystal ◽

Three Dimensional ◽

Band Gaps ◽

Acoustic Properties ◽

Bragg Scattering ◽

Wavelength Band ◽

Local Resonance ◽

Scattering Effects ◽

Acoustic Speed ◽

Sub Wavelength

Abstract Three-dimensional (3D) locally resonant phononic crystals (LRPCs) are studied with the aim of optimising the sub-wavelength band gaps of such composites. By analysing their effective acoustic properties, it has been found that the effective acoustic speed of the composite will drop to zero when local resonance arise, and will increase monotonically when Bragg scattering effects occur. Moreover, if the matrix is a low-shear-speed medium, local resonators can significantly reduce the effective acoustic speed of the composite and, therefore, lower the frequency where Bragg scattering effects occur. Hence, a specific LRPC with alternating elastic and fluid matrices is proposed, whose resonance and Bragg gaps are already close in frequency. The fluid matrix behaves as a wave filter, which prevents the shear waves from propagating in the composite. By using the layer-multiple-scattering theory, the coupling behaviour of local resonance and Bragg scattering band gaps has been investigated. Both gaps are enhanced when they move closer to each other. Finally, a gap-coupled case is obtained that displays a broad sub-wavelength band gap. Such proposal excels at the application of underwater acoustic materials since the arrangement of structure can be handily adjusted for tuning the frequency of coupled gap.

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A High-Frequency Homogenization Approach Near the Dirac Points in Bubbly Honeycomb Crystals

Archive for Rational Mechanics and Analysis ◽

10.1007/s00205-020-01572-w ◽

2020 ◽

Vol 238 (3) ◽

pp. 1559-1583 ◽

Cited By ~ 1

Author(s):

Habib Ammari ◽

Erik Orvehed Hiltunen ◽

Sanghyeon Yu

Keyword(s):

High Frequency ◽

Arbitrary Shape ◽

Phononic Crystal ◽

The Other ◽

Numerical Examples ◽

Dirac Equations ◽

Homogenization Approach ◽

First Time ◽

Compare And Contrast ◽

Sub Wavelength

Abstract In (Ammari et al. in SIAM J Math Anal. arXiv:1811.03905), the existence of a Dirac dispersion cone in a bubbly honeycomb phononic crystal comprised of bubbles of arbitrary shape is shown. The aim of this paper is to prove that, near the Dirac points, the Bloch eigenfunctions is the sum of two eigenmodes. Each eigenmode can be decomposed into two components: one which is slowly varying and satisfies a homogenized equation, while the other is periodic across each elementary crystal cell and is highly oscillating. The slowly oscillating components of the eigenmodes satisfy a system of Dirac equations. Our results in this paper prove for the first time a near-zero effective refractive index near the Dirac points for the plane-wave envelopes of the Bloch eigenfunctions in a sub-wavelength metamaterial. They are illustrated by a variety of numerical examples. We also compare and contrast the behaviour of the Bloch eigenfunctions in the honeycomb crystal with that of their counterparts in a bubbly square crystal, near the corner of the Brillouin zone, where the maximum of the first Bloch eigenvalue is attained.

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Phononic-Crystal Acoustic Lens by Design for Energy-Transmission Devices

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.132.686 ◽

2012 ◽

Vol 132 (5) ◽

pp. 686-690

Author(s):

Yusuke Kanno ◽

Kenji Tsuruta ◽

Kazuhiro Fujimori ◽

Hideki Fukano ◽

Shigeji Nogi

Keyword(s):

Phononic Crystal ◽

Energy Transmission ◽

Acoustic Lens

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Canalization of Sub-wavelength Images by Electromagnetic Crystals

PIERS Online ◽

10.2529/piers041207044900 ◽

2005 ◽

Vol 1 (1) ◽

pp. 37-41 ◽

Cited By ~ 3

Author(s):

Pavel A. Belov ◽

C. R. Simovski

Keyword(s):

Electromagnetic Crystals ◽

Sub Wavelength

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Flexural Wave Band Gaps in Phononic Crystal Thick Plates with Defects

10.26678/abcm.diname2019.din2019-0002 ◽

2019 ◽

Author(s):

Edson Jansen Pedrosa de Miranda Junior ◽

Jose Maria Campos dos Santos

Keyword(s):

Phononic Crystal ◽

Band Gaps ◽

Flexural Wave ◽

Wave Band ◽

Thick Plates

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Design of Resonant Sub-Wavelength Metallic Apertures to Enable Higher Resolution Sensor Arrays

10.21236/ada563980 ◽

2012 ◽

Author(s):

Aydogan Ozcan

Keyword(s):

Sensor Arrays ◽

Sub Wavelength

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Tunable characteristics of low-frequency bandgaps in two-dimensional multivibrator phononic crystal plates under prestrain

Scientific Reports ◽

10.1038/s41598-021-87904-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hai-Fei Zhu ◽

Xiao-Wei Sun ◽

Ting Song ◽

Xiao-Dong Wen ◽

Xi-Xuan Liu ◽

...

Keyword(s):

Phononic Crystal ◽

Real Life ◽

Low Frequency ◽

Acoustic Vibration ◽

Crystal Plate ◽

Frequency Noise ◽

Two Dimensional ◽

The Matrix ◽

Noise Frequency ◽

Realtime Control

AbstractIn view of the influence of variability of low-frequency noise frequency on noise prevention in real life, we present a novel two-dimensional tunable phononic crystal plate which is consisted of lead columns deposited in a silicone rubber plate with periodic holes and calculate its bandgap characteristics by finite element method. The low-frequency bandgap mechanism of the designed model is discussed simultaneously. Accordingly, the influence of geometric parameters of the phononic crystal plate on the bandgap characteristics is analyzed and the bandgap adjustability under prestretch strain is further studied. Results show that the new designed phononic crystal plate has lower bandgap starting frequency and wider bandwidth than the traditional single-sided structure, which is due to the coupling between the resonance mode of the scatterer and the long traveling wave in the matrix with the introduction of periodic holes. Applying prestretch strain to the matrix can realize active realtime control of low-frequency bandgap under slight deformation and broaden the low-frequency bandgap, which can be explained as the multiple bands tend to be flattened due to the localization degree of unit cell vibration increases with the rise of prestrain. The presented structure improves the realtime adjustability of sound isolation and vibration reduction frequency for phononic crystal in complex acoustic vibration environments.

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