scholarly journals Manipulation of acoustic focusing with an active and configurable planar metasurface transducer

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Jiajun Zhao ◽  
Huapeng Ye ◽  
Kun Huang ◽  
Zhi Ning Chen ◽  
Baowen Li ◽  
...  
Keyword(s):  
Acoustic Focusing

Broadband acoustic focusing via binary rectangular cavity/Helmholtz resonator metasurface

2021 ◽  
Vol 129 (15) ◽  
pp. 155307
Author(s):  
Shuai Tang ◽  
Bin Ren ◽  
Yuxin Feng ◽  
Jie Song ◽  
Yongyuan Jiang
Keyword(s):  
Helmholtz Resonator ◽  
Rectangular Cavity ◽  
Acoustic Focusing

scholarly journals Acoustic Focusing with Intensity Modulation Based on Sub-Wavelength Waveguide Array

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1461
Author(s):  
Mingran Zhang ◽  
Guangrui Gu
Keyword(s):  
Focal Length ◽  
Intensity Modulation ◽  
Waveguide Array ◽  
Refractive Index Modulation ◽  
Destructive Testing ◽  
Equivalent Impedance ◽  
Coding Method ◽  
Acoustic Focusing ◽  
Arbitrary Amplitude ◽  
Sub Wavelength

Acoustic focusing with intensity modulation plays an important role in biomedical and life sciences. In this work, we propose a new approach for simultaneous phase and amplitude manipulation in sub-wavelength coupled resonant units, which has not been reported so far. Based on the equivalent impedance and refractive index modulation induced by the change of geometry, arbitrary amplitude response from 0 to 1 and phase shift from 0 to 2π is realized. Thus, the acoustic focusing with intensity modulation can be achieved via waveguide array. Herein, the focal length can be adjusted by alternating the length of supercell, and the whole system can work in a broadband of 0.872f0–1.075f0. By introducing the coding method, the thermal viscosity loss is reduced, and the wavefront modulation can be more accurate. Compared with previous works, our approach has the advantages of simple design and broadband response, which may have promising applications in acoustic communication, non-destructive testing, and acoustic holography.

Organization and Compaction of Composite Filler Material Using Acoustic Focusing

2017 ◽  
Author(s):  
Lauren A. Chai ◽  
Brian W. Anthony
Keyword(s):  
Electrical Resistivity ◽  
Carbon Nanofibers ◽  
Electrical Resistance ◽  
Volume Fraction ◽  
Acoustic Radiation ◽  
Mineral Oil ◽  
Acoustic Focusing ◽  
Initial Drop ◽  
Light Mineral ◽  
External Face

Carbon nanofibers in polymer-based composites reduce the electrical resistivity of the composite but can be up to 100 times more expensive than the bulk polymer. This work uses acoustic focusing to organize and compact carbon nanofibers in a mineral oil mixture. The result is a decrease in the composite electrical resistivity without an increase in the global volume fraction of the fibers in the composite and associated material cost. The composite consisted of Pyrograf PR-19-LHT carbon nanofibers mixed in light mineral oil at 1.6% volume fraction carbon nanofibers. The mixture was contained in a 1 cm × 1 cm × 4 cm glass cuvette. A PZT-4 piezoelectric transducer, epoxied to the external face of one of the sidewalls, generated the acoustic radiation forces in the container. A 1.179 MHz sinusoidal signal powered the transducer, producing a standing wave with 27 nodes and 13 antinodes in the container. A digital multimeter performed the 2-wire resistance measurement before, during and after focusing. Settling of the filler due to gravity resulted in an initial drop in the electrical resistance. Once the mixture reached steady state, toggling the signal power off and on also toggled the approximate electrical resistance between the 19.2 MOhms and 11.5 MOhms respectively. This work also presents a simple volume fraction model, which predicted that the focused resistance would be 34% of the unfocused value. In the experiment, acoustic focusing reduced the electrical resistance to 60% of the resistance in the unfocused mixture, demonstrating acoustic focusing as a method for reducing electrical conductivity within a composite.

scholarly journals Numerical study of acoustic focusing using a bianisotropic acoustic lens

2020 ◽  
Vol 148 (4) ◽  
pp. EL365-EL369
Author(s):  
A. J. Lawrence ◽  
Benjamin M. Goldsberry ◽  
Samuel P. Wallen ◽  
Michael R. Haberman
Keyword(s):  
Numerical Study ◽  
Acoustic Lens ◽  
Acoustic Focusing

Feature

2010 ◽  
Vol 14 (11) ◽  
pp. 18-27
Keyword(s):  
Genetic Diversity ◽  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Spectral Imaging ◽  
Advanced Renal Cell Carcinoma ◽  
Acoustic Focusing

Neem: A Wonder Tree. Bacteria Living on Arsenic Discovered. Temsirolimus Approved in Singapore for Advanced Renal Cell Carcinoma. Attune™ Acoustic Focusing Cytometer. Securing Genetic Diversity of Rice in 'Doomsday Vault'. Leica Opens New Dimension in Spectral Imaging.

One-dimensional single-sided acoustic focusing in a Goupillaud layered model

2014 ◽  
Vol 136 (5) ◽  
pp. 2381-2388 ◽  
Author(s):  
Yinquan Zhang ◽  
Ning Wang ◽  
Pengyu Wang
Keyword(s):  
One Dimensional ◽  
Layered Model ◽  
Acoustic Focusing

Wave Beaming in Nanostructured Materials With Engineered Defects

2008 ◽  
Author(s):  
Mahmoud I. Hussein ◽  
Michael J. Leamy ◽  
Massimo Ruzzene
Keyword(s):  
Periodic Structures ◽  
Graphene Nanosheets ◽  
Low Frequency ◽  
Two Dimensional ◽  
Propagation Characteristics ◽  
Nanoscale Material ◽  
Material Systems ◽  
Acoustic Focusing ◽  
Acoustic Waveguides ◽  
Draft Paper

Recent advances in the fabrication of nanoscale material systems have made it possible to alter precisely the atomic structure in ways that enhance the properties and allow for certain functions to be realized. This work is concerned with two-dimensional periodic structures and emphasizes the effects of intentional defects on their wave propagation characteristics. In this draft paper, investigations are limited to a two-dimensional spring-mass lattice, composed of “super-cells” where mass inclusions are added to alter band-gap properties, as well as low frequency directionality. The presented results will then be extended to two-dimensional nanostructures, such as graphene nanosheets, in order to investigate their application as nanoscale acoustic waveguides, where engineered defects, uniformally distributed across the entire sheet, are introduced by design with the objective of rendering the medium anisotropic. Such anisoptropy leads to acoustic directionality, which can be exploited for waveguiding or acoustic-focusing purposes.

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