Numerical models for evaluating the vibro‐acoustic properties of acoustic metamaterials

Quirin Aumann; Matthias Miksch; Gerhard Müller

doi:10.1002/pamm.201800174

Acoustic manipulation of fractal metamaterials with negative properties and near-zero densities

Applied Physics Express ◽

10.35848/1882-0786/ac4301 ◽

2021 ◽

Author(s):

Guanghua Wu ◽

Yibo Ke ◽

Lin Zhang ◽

Meng Tao

Keyword(s):

High Potential ◽

Experimental Results ◽

Acoustic Properties ◽

Sound Insulation ◽

Sound Waves ◽

Acoustic Metamaterials ◽

Acoustic Device

Abstract Acoustic metamaterials have high potential in diverse applications, including acoustic cloaking, sound tunneling, wavefront reshaping, and sound insulation. In the present study, new metamaterials consisting of spatial coiled units are designed and fabricated to manipulate sound waves in the range 0-1600 Hz. The effective acoustic properties and band diagrams are studied. The simulation and experimental results demonstrate that the metamaterials provide an effective and feasible approach to design acoustic device such as sound cloaking and insulators.

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Shear-mediated contributions to the effective properties of soft acoustic metamaterials including negative index

Scientific Reports ◽

10.1038/srep18562 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 9

Author(s):

Derek Michael Forrester ◽

Valerie J. Pinfield

Keyword(s):

Effective Properties ◽

Acoustic Properties ◽

Double Negative ◽

Acoustic Metamaterials ◽

Viscous Losses ◽

Backward Propagation ◽

Phase Angles ◽

Lossy Materials ◽

Selection Of ◽

Sub Wavelength

Abstract Here we show that, for sub-wavelength particles in a fluid, viscous losses due to shear waves and their influence on neighbouring particles significantly modify the effective acoustic properties and thereby the conditions at which negative acoustic refraction occurs. Building upon earlier single particle scattering work, we adopt a multiple scattering approach to derive the effective properties (density, bulk modulus, wavenumber). We show,through theoretical prediction, the implications for the design of “soft” (ultrasonic) metamaterials based on locally-resonant sub-wavelength porous rubber particles, through selection of particle size and concentration and demonstrate tunability of the negative speed zones by modifying the viscosity of the suspending medium. For these lossy materials with complex effective properties, we confirm the use of phase angles to define the backward propagation condition in preference to “single-” and “double-negative” designations.

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Predicting double negativity using transmitted phase in space coiling metamaterials

Royal Society Open Science ◽

10.1098/rsos.171042 ◽

2018 ◽

Vol 5 (5) ◽

pp. 171042 ◽

Cited By ~ 1

Author(s):

Santosh K. Maurya ◽

Abhishek Pandey ◽

Shobha Shukla ◽

Sumit Saxena

Keyword(s):

Acoustic Waves ◽

Negative Refraction ◽

Acoustic Properties ◽

Propagation Path ◽

Elastic Response ◽

Acoustic Metamaterials ◽

Effective Response ◽

Retrieval Method ◽

S Parameter ◽

Parameter Retrieval

Metamaterials are engineered materials that offer the flexibility to manipulate the incident waves leading to exotic applications such as cloaking, extraordinary transmission, sub-wavelength imaging and negative refraction. These concepts have largely been explored in the context of electromagnetic waves. Acoustic metamaterials, similar to their optical counterparts, demonstrate anomalous effective elastic properties. Recent developments have shown that coiling up the propagation path of acoustic wave results in effective elastic response of the metamaterial beyond the natural response of its constituent materials. The effective response of metamaterials is generally evaluated using the ‘S’ parameter retrieval method based on amplitude of the waves. The phase of acoustic waves contains information of wave pressure and particle velocity. Here, we show using finite-element methods that phase reversal of transmitted waves may be used to predict extreme acoustic properties in space coiling metamaterials. This change is the difference in the phase of the transmitted wave with respect to the incident wave. This method is simpler when compared with the more rigorous ‘S’ parameter retrieval method. The inferences drawn using this method have been verified experimentally for labyrinthine metamaterials by showing negative refraction for the predicted band of frequencies.

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Additive Manufacture of Small-Scale Metamaterial Structures for Acoustic and Ultrasonic Applications

Micromachines ◽

10.3390/mi12060634 ◽

2021 ◽

Vol 12 (6) ◽

pp. 634

Author(s):

Alicia Gardiner ◽

Paul Daly ◽

Roger Domingo-Roca ◽

James F. C. Windmill ◽

Andrew Feeney ◽

...

Keyword(s):

Large Scale ◽

Acoustic Properties ◽

Small Scale ◽

Additive Manufacture ◽

Acoustic Metamaterials ◽

Acoustic Metamaterial ◽

Multi Scale ◽

Advantages And Disadvantages ◽

Scale Structures ◽

Small Scale Structures

Acoustic metamaterials are large-scale materials with small-scale structures. These structures allow for unusual interaction with propagating sound and endow the large-scale material with exceptional acoustic properties not found in normal materials. However, their multi-scale nature means that the manufacture of these materials is not trivial, often requiring micron-scale resolution over centimetre length scales. In this review, we bring together a variety of acoustic metamaterial designs and separately discuss ways to create them using the latest trends in additive manufacturing. We highlight the advantages and disadvantages of different techniques that act as barriers towards the development of realisable acoustic metamaterials for practical audio and ultrasonic applications and speculate on potential future developments.

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Wave propagation control in active acoustic metamaterials

Journal of Physics Conference Series ◽

10.1088/1742-6596/2015/1/012031 ◽

2021 ◽

Vol 2015 (1) ◽

pp. 012031

Author(s):

A. Bacigalupo ◽

M. L. De Bellis ◽

G. Gnecco ◽

D. Misseroni

Keyword(s):

Wave Propagation ◽

Real Time ◽

High Performance ◽

Electrical Circuit ◽

Acoustic Properties ◽

Acoustic Metamaterials ◽

Piezoelectric Phase ◽

Active Acoustic Metamaterials ◽

Opening Up

Abstract Focus is on the design of an innovative class of tunable periodic metamaterials, conceived for the realization of high performance acoustic metafilters with settable real-time capabilities. In this framework the tunability is due to the presence of a piezoelectric phase shunted by a suitable electrical circuit with adjustable impedance/admittance. It follows that the acoustic properties of the metamaterial can be properly modified in an adaptive way, opening up new possibilities for the control of pass- and stop-bands.

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A Review of Acoustic Metamaterials and Phononic Crystals

Crystals ◽

10.3390/cryst10040305 ◽

2020 ◽

Vol 10 (4) ◽

pp. 305 ◽

Cited By ~ 1

Author(s):

Junyi Liu ◽

Hanbei Guo ◽

Ting Wang

Keyword(s):

Physical Properties ◽

Negative Refraction ◽

Phononic Crystals ◽

Acoustic Properties ◽

Acoustic Metamaterials ◽

Acoustic Metamaterial ◽

Great Progress ◽

Practical Engineering ◽

Promising Application ◽

Made In

As a new kind of artificial material developed in recent decades, metamaterials exhibit novel performance and the promising application potentials in the field of practical engineering compared with the natural materials. Acoustic metamaterials and phononic crystals have some extraordinary physical properties, effective negative parameters, band gaps, negative refraction, etc., extending the acoustic properties of existing materials. The special physical properties have attracted the attention of researchers, and great progress has been made in engineering applications. This article summarizes the research on acoustic metamaterials and phononic crystals in recent decades, briefly introduces some representative studies, including equivalent acoustic parameters and extraordinary characteristics of metamaterials, explains acoustic metamaterial design methods, and summarizes the technical bottlenecks and application prospects.

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Design, Manufacturing, and Acoustical Analysis of a Helmholtz Resonator-Based Metamaterial Plate

Acoustics ◽

10.3390/acoustics3040040 ◽

2021 ◽

Vol 3 (4) ◽

pp. 630-641

Author(s):

Sourabh Dogra ◽

Arpan Gupta

Keyword(s):

Transmission Loss ◽

Sound Transmission ◽

Helmholtz Resonator ◽

Acoustic Properties ◽

Sound Transmission Loss ◽

Sound Waves ◽

Acoustic Metamaterials ◽

Additional Advantage ◽

Helmholtz Resonators ◽

High Sound

Acoustic metamaterials are materials artificially engineered to control sound waves, which is not possible with conventional materials. We have proposed a design of an acoustic metamaterial plate with inbuilt Helmholtz resonators. The plate is made of Polylactic acid (PLA) which is fabricated using an additive manufacturing technique. It consists of Helmholtz resonator-shaped cavities of different sizes. In this paper, we have analyzed the acoustic properties of the Helmholtz resonators-based metamaterial plate experimentally as well as numerically. The experimental results are in good agreement with the numerical results. These types of 3D-printed metamaterial plates can find their application where high sound transmission loss is required to create a quieter ambience. There is an additional advantage of being lightweight because of the Helmholtz resonator-shaped cavities built inside the plate. Thus, these types of metamaterial plates can find their application in the design sector requiring lighter materials with high sound transmission loss.

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