scholarly journals A Review of Acoustic Metamaterials and Phononic Crystals

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 305 ◽  
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.

scholarly journals Predicting double negativity using transmitted phase in space coiling metamaterials

2018 ◽  
Vol 5 (5) ◽  
pp. 171042 ◽  
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.

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

Micromachines ◽  
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.

scholarly journals Low-frequency perfect sound absorption achieved by a modulus-near-zero metamaterial

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chen Shao ◽  
Houyou Long ◽  
Ying Cheng ◽  
Xiaojun Liu
Keyword(s):  
Imaginary Part ◽  
Low Frequency ◽  
Destructive Interference ◽  
Perfect Absorber ◽  
Acoustic Metamaterials ◽  
Perfect Absorption ◽  
Acoustic Metamaterial ◽  
Dissipative Loss ◽  
Great Consistency ◽  
Practical Engineering

Abstract We have analytically proposed a mechanism for achieving a perfect absorber by a modulus-near-zero (MNZ) metamaterial with a properly decorated imaginary part, in which the perfect absorption (PA) is derived from the proved destructive interference. Based on the analysis, an ultrathin acoustic metamaterial supporting monopolar resonance at 157 Hz (with a wavelength about 28 times of the metamaterial thickness) has been devised to construct an absorber for low-frequency sound. The imaginary part of its effective modulus can be easily tuned by attentively controlling the dissipative loss to achieve PA. Moreover, we have also conducted the experimental measurement in impedance tube, and the result is of great consistency with that of analytical and simulated ones. Our work provides a feasible approach to realize PA (>99%) at low frequency with a deep-wavelength dimension which may promote acoustic metamaterials to practical engineering applications in noise control.

An Acoustic Hyperlens with Negative Direction Based on Double Split Hollow Sphere

2019 ◽  
Vol 27 (02) ◽  
pp. 1850025
Author(s):  
Jung Sik Choi ◽  
Gil Ho Yoon
Keyword(s):  
Hollow Sphere ◽  
Negative Refraction ◽  
Diffraction Limit ◽  
Original Form ◽  
Acoustic Metamaterials ◽  
Relevant Research ◽  
Unusual Behavior ◽  
Acoustic Metamaterial ◽  
Helmholtz Resonators ◽  
Unit Structure

This study develops a new acoustic negative-refraction metamaterial that utilizes a synthesized double split hollow sphere (DSHS) for its unit cell. Recent relevant research has affirmed the concept that acoustic metamaterials can show unusual behavior that has not been observed in nature previously. However, as some hypothetical metamaterial designs have material properties not found in nature, the realization of practical metamaterials requires practical and complicated models. As a contribution to the development of acoustic metamaterials, the present study proposes a new anisotropic unit structure that encompasses Helmholtz resonators. This structure is referred to as the DSHS, is easy to manufacture, and has the advantage in that it uses the natural medium in its original form. By drawing the equifrequency or isofrequency contours of the designed two-dimensional (2D) anisotropic unit structure using the Floquet–Bloch’s principle, the properties of the present metamaterial can be understood. Numerical simulations are also conducted to identify and present the characteristics of the presented acoustic metamaterial. Through these, a new refraction phenomenon is identified that deviates from Snell’s law, and an acoustic hyperlens is numerically implemented that overcomes the diffraction limit.

WIELAND-SW1

Alloy Digest ◽  
2015 ◽  
Vol 64 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Lead Free ◽  
Made In

Abstract Wieland-SW1 is a lead-free special brass made in extruded and drawn products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Cu-841. Producer or source: Wieland Metals Inc. and Wieland-Werke AG.

MULTIMET (N-155)

Alloy Digest ◽  
1961 ◽  
Vol 10 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Age Hardening ◽  
Nickel Chromium ◽  
Cobalt Nickel ◽  
Temperature Performance ◽  
High Oxidation ◽  
Scaling Resistance ◽  
Made In

Abstract MULTIMET alloy is cobalt-nickel-chromium-iron austenitic alloy having high oxidation and scaling resistance along with good high-temperature properties. It tends to work harden but does not respond significantly to age-hardening. It is made in a wrought grade (0.08-0.16% carbon) and a casting grade (0.20% max. carbon). This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SS-28. Producer or source: Haynes Stellite Company. Originally published May 1955, revised December 1961.

scholarly journals Pathogenesis and Potential Therapeutic Targets for Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2978
Author(s):  
Chia-Jung Li ◽  
Yen-Dun Tony Tzeng ◽  
Yi-Han Chiu ◽  
Hung-Yu Lin ◽  
Ming-Feng Hou ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Targeted Therapy ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
High Efficiency ◽  
Early Recurrence ◽  
New Developments ◽  
Great Progress ◽  
Low Toxicity ◽  
Made In

Triple negative breast cancer (TNBC) is a heterogeneous tumor characterized by early recurrence, high invasion, and poor prognosis. Currently, its treatment includes chemotherapy, which shows a suboptimal efficacy. However, with the increasing studies on TNBC subtypes and tumor molecular biology, great progress has been made in targeted therapy for TNBC. The new developments in the treatment of breast cancer include targeted therapy, which has the advantages of accurate positioning, high efficiency, and low toxicity, as compared to surgery, radiotherapy, and chemotherapy. Given its importance as cancer treatment, we review the latest research on the subtypes of TNBC and relevant targeted therapies.

scholarly journals Research Progress and Development Trends of Acoustic Metamaterials

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4018
Author(s):  
Hao Song ◽  
Xiaodong Ding ◽  
Zixian Cui ◽  
Haohao Hu
Keyword(s):  
Doppler Effect ◽  
Negative Refraction ◽  
Development Trend ◽  
Atomic Clusters ◽  
Research Progress ◽  
Acoustic Metamaterials ◽  
Development Trends ◽  
Related Research ◽  
The Past ◽  
Anomalous Doppler Effect

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.

Rhodium-Catalyzed, Phosphorus(III)-Directed Hydroarylation of Internal Alkynes: Facile and Efficient Access to New Phosphine Ligands

Synlett ◽  
2020 ◽  
Author(s):  
Minyan Wang ◽  
Zhuangzhi Shi ◽  
Huanhuan Luo ◽  
Dawei Wang
Keyword(s):  
High Selectivity ◽  
Enantiomeric Excess ◽  
Phosphine Ligands ◽  
Rapid Construction ◽  
Efficient Access ◽  
Internal Alkynes ◽  
Great Progress ◽  
Chiral Phosphine Ligands ◽  
Optimized Conditions ◽  
Made In

AbstractOrganophosphines are an important class of ligands widely used in organic chemistry. Although great progress has recently been made in the rapid construction of new phosphines through Rh- or Ru-catalyzed C–H bond functionalizations, synthetic access to more diverse phosphines remains a challenge. We describe an efficient process for the rhodium-catalyzed phosphorus(III)-directed hydroarylation of internal alkynes to generate various alkenylated and 2′,6′-dialkenylated biarylphosphines with high selectivity. A range of diverse alkynes and phosphines were effectively prepared with broad functional-group compatibility under the optimized conditions. In addition, the developed protocol can be extended to modify chiral phosphine ligands, providing enantioenriched alkenylated phosphines without erosion of the enantiomeric excess.

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