Acoustic cloaking transformations from attainable material properties
Repository Usage Stats
We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented here are designed and function analogously to electromagnetic cloaks. However, acoustic cloaks in a fluid medium do not suffer the bandwidth limitations imposed on their electromagnetic counterparts by the finite speed of light in vacuum. In the absence of specific metamaterials having arbitrary combinations of quasi-static speed of sound and mass density, we explore the flexibility of continuum transformations that produce approximate cloaking solutions. We show that an imperfect, eikonal acoustic cloak (that is, one which is not impedance matched but is valid in the geometrical optics regime) with negligible dispersion can be designed using a simple layered geometry. Since a practical cloaking device will probably be composed of combinations of solid materials rather than fluids, it is necessary to consider the full elastic properties of such media, which support shear waves in addition to the compression waves associated with the acoustic regime. We perform a systematic theoretical and numerical investigation of the role of shear waves in elastic cloaking devices. We find that for elastic metamaterials with Poisson's ratio v > 0.49, shear waves do not alter the cloaking effect. Such metamaterials can be built from nearly incompressible rubbers (with v ≈ 0.499) and fluids. We expect this finding to have applications in other acoustic devices based on the form-invariance of the scalar acoustic wave equation. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
Published Version (Please cite this version)10.1088/1367-2630/12/7/073014
Publication InfoUrzhumov, Y; Ghezzo, F; Hunt, J; & Smith, DR (2010). Acoustic cloaking transformations from attainable material properties. New Journal of Physics, 12. pp. 1-21. 10.1088/1367-2630/12/7/073014. Retrieved from https://hdl.handle.net/10161/5078.
This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.
More InfoShow full item record
James B. Duke Distinguished Professor of Electrical and Computer Engineering
Dr. David R. Smith is currently the James B. Duke Professor of Electrical and Computer Engineering Department at Duke University. He is also Director of the Center for Metamaterials and Integrated Plasmonics at Duke and holds the positions of Adjunct Associate Professor in the Physics Department at the University of California, San Diego, and Visiting Professor of Physics at Imperial College, London. Dr. Smith received his Ph.D. in 1994 in Physics from the University of California, San Dieg
Adjunct Assistant Professor in the Department of Electrical and Computer Engineering
<!--[if gte mso 9]> <![endif]--> <!--[if gte mso 9]> <![endif]-->Dr. Urzhumov is Adjunct Assistant Professor of ECE at Duke University, and also a Technologist at the Metamaterials Commercialization Center of Intellectual Ventures. Previously a research faculty at Duke, he works on applied and theoretical aspects of metama
Alphabetical list of authors with Scholars@Duke profiles.