One path to acoustic cloaking
Steven A. Cummer,David Schurig +1 more
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TLDR
In this paper, it was shown that the acoustic equations in a fluid are identical in form to the single polarization Maxwell equations via a variable exchange that also preserves boundary conditions, and the existence of transformation-type solutions for the 2D acoustic equations with anisotropic mass via time harmonic simulations of acoustic cloaking.Abstract:
A complete analysis of coordinate transformations in elastic media by Milton et al has shown that, in general, the equations of motion are not form invariant and thus do not admit transformation-type solutions of the type discovered by Pendry et al for electromagnetics. However, in a two-dimensional (2D) geometry, the acoustic equations in a fluid are identical in form to the single polarization Maxwell equations via a variable exchange that also preserves boundary conditions. We confirm the existence of transformation-type solutions for the 2D acoustic equations with anisotropic mass via time harmonic simulations of acoustic cloaking. We discuss the possibilities of experimentally demonstrating acoustic cloaking and analyse why this special equivalence of acoustics and electromagnetics occurs only in 2D.read more
Citations
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Transformation optics for thermoelectric flow
TL;DR: In this article, a unified description of transformation optics to thermoelectricity within the framework of thermodynamics is presented, and the authors apply transformation optics for modifying diffusive transport, such as heat and electricity.
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Acoustic conjugate metamaterials
Liang Chen,Li Fan,Shu-yi Zhang +2 more
TL;DR: In this paper, the authors presented acoustic conjugate metamaterials, which possess complex mass densities and bulk compressibilities with opposite phases, to manipulate acoustic waves by adjusting the phases of the complex material parameters.
Book ChapterDOI
Chapter 5 - Transformation Optics
TL;DR: Transformation optics as mentioned in this paper is a new way of designing novel optical and electromagnetic devices based on the idea of using coordinate transformations to generate descriptions of dielectric media, which allows for essentially complete control over the behavior of electromagnetic fields through a suitable choice of medium, determined by a transformation that can specify the trajectories of light rays, the orientation of phase fronts, or other geometrical features of the fields.
Journal ArticleDOI
Design of arbitrarily shaped acoustic cloaks through partial differential equation-constrained optimization satisfying sonic-metamaterial design requirements
TL;DR: In this article , an optimization framework for the design of acoustic cloaks is developed, with the aim of overcoming the limitations of usual transformation-based cloaks in terms of microstructure complexity and shape arbitrarity of the obstacle.
References
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TL;DR: In this paper, it was shown that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu/sub eff/, which can be tuned to values not accessible in naturally occurring materials.
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Controlling Electromagnetic Fields
TL;DR: This work shows how electromagnetic fields can be redirected at will and proposes a design strategy that has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
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Metamaterial Electromagnetic Cloak at Microwave Frequencies
David Schurig,Jack J. Mock,B.J. Justice,Steven A. Cummer,John B. Pendry,Anthony F. Starr,David R. Smith +6 more
TL;DR: This work describes here the first practical realization of a cloak of invisibility, constructed with the use of artificially structured metamaterials, designed for operation over a band of microwave frequencies.
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Optical Conformal Mapping
TL;DR: A general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics is developed, which can be applied to escape detection by other electromagnetic waves or sound.
Journal ArticleDOI
Ultrasonic metamaterials with negative modulus
Nicholas X. Fang,Dongjuan Xi,Jianyi Xu,Muralidhar Ambati,Werayut Srituravanich,Cheng Sun,Xiang Zhang +6 more
TL;DR: A new class of ultrasonic metamaterials consisting of an array of subwavelength Helmholtz resonators with designed acoustic inductance and capacitance with an effective dynamic modulus with negative values near the resonance frequency is reported.