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Conclusion
Cloaking of sound, first proposed only seven years ago, has been shown to be feasible with practical demonstrations ap- pearing regularly and more frequently. How will this emerg- ing acoustic technology impact society? We can expect ap- plications in improved noise reduction, sound absorbtion, architectural acoustics, and envornmental acoustics, not to mention defense interest in underwater sound control.
Acknowledgment
Thanks to Adam Nagy and Xiaoshi Su for discussions and graphical assistance. This work was supported by ONR MURI Grant No. N000141310631.
Biosketch
Andrew Norris received the BSc and MSc in Mathematical Physics from University College Dublin, and the PhD from Northwestern Uni- versity in 1981. Following a post- doc at Exxon Research and Engi- neering Corporate Laboratories he joined Rutgers University where he is now Professor of Mechanical and Aerospace Engineering. He has worked on geophysical, structural
and ultrasonic NDE wave problems. His current interests are in metamaterials that exhibit extraordinary wave bear- ing properties. He is editor of Wave Motion, an Associate Editor of JASA and a Fellow of the ASA. In his off time he enjoys reading, running and the great outdoors.
References
Beilis, A., Tappert, F. D. (1979). “Coupled mode analysis of multiple rough surface scattering.” Journal of the Acoustical Society of America 66, 811–826.
Bobrovnitskii, Y. (2010). “Impedance acoustic cloaking.” New Journal of Physics 12, 043049+.
Brûlé, S., Javelaud, E. H., Enoch, S., Guenneau, S. (2014). “Experiments on seismic metamaterials: Molding surface waves.” Physical Review Letters 112, 133901+.
Brun, M., Guenneau, S., Movchan, A. B. (2009). “Achieving control of in- plane elastic waves.” Applied Physics Letters 94, 061903+.
Bückmann, T., Thiel, M., Kadic, M., Schittny, R., Wegener, M. (2014). “An elasto-mechanical unfeelability cloak made of pentamode metamaterials.” Nature Communications 5, 4130+.
Chen, H., Chan, C. T. (2007). “Acoustic cloaking in three dimensions using acoustic metamaterials.” Applied Physics Letters 91, 183518+.
Chen, H., Chan, C. T. (2010). “Acoustic cloaking and transformation acous- tics.” Journal of Physics D 43, 113001+.
Craster, R. V., Guenneau, S., editors (2013). Acoustic Metamaterials, vol. 166 of Springer Series in Materials Science (Springer).
Cummer, S. A., Schurig, D. (2007). “One path to acoustic cloaking.” New Journal of Physics 9, 45+.
Farhat, M., Enoch, S., Guenneau, S., Movchan, A. B. (2008). “Broadband cy- lindrical acoustic cloak for linear surface waves in a fluid.” Physical Review Letters 101, 134501+.
Farhat, M., Guenneau, S., Enoch, S., Movchan, A. B. (2009). “Cloaking bending waves propagating in thin elastic plates.” Physical Review B 79, 033102+.
Fleury, R., Alù, A. (2013). “Cloaking and invisibility: A review.” Forum for Elec- tromagnetic Research Methods and Application Technologies (FERMAT).
García-Chocano, V. M., Sanchis, L., Díaz-Rubio, A., Martínez-Pastor, J., Cervera, F., Llopis-Pontiveros, R., Sánchez-Dehesa, J. (2011). “Acoustic cloak for airborne sound by inverse design.” Applied Physics Letters 99, 074102+.
García-Chocano, V. M., Torrent, D., Sánchez-Dehesa, J. (2012). “Reduced acoustic cloaks based on temperature gradients.” Applied Physics Letters 101, 084103+.
Guevara Vasquez, F., Milton, G. W., Onofrei, D. (2011). “Exterior cloak- ing with active sources in two dimensional acoustics.” Wave Motion 49, 515–524.
Guild, M. D., Alu, A., Haberman, M. R. (2011). “Cancellation of acoustic scattering from an elastic sphere.” Journal of the Acoustical Society of Amer- ica 129, p. 1355.
Guild, M. D., Alù, A., Haberman, M. R. (2014). “Cloaking of an acous- tic sensor using scattering cancellation.” Applied Physics Letters 105, 023510+.
Hu, W., Fan, Y., Ji, P., Yang, J. (2013). “An experimental acoustic cloak for generating virtual images.” Journal of Applied Physics 113, 024911+.
Huang, X., Zhong, S., Stalnov, O. (2014). “Analysis of scattering from an acoustic cloak in a moving fluid.” Journal of the Acoustical Society of Amer- ica 135, 2571–2580
Kadic, M., Bückmann, T., Schittny, R., Wegener, M. (2013). “Metama- terials beyond electromagnetism.” Reports on Progress in Physics 76, 126501+.
Kan, W., Liang, B., Zhu, X., Li, R., Zou, X., Wu, H., Yang, J., Cheng, J. (2013). “Acoustic illusion near boundaries of arbitrary curved geometry.” Scien- tific Reports 3, p. 1427.
Kim, S.-H., Das, M. P. (2013). “Artificial seismic shadow zone by acoustic metamaterials.” Mod Phys Lett B 27, 1350140+.
Layman, C. N., Naify, C. J., Martin, T. P., Calvo, D. C., Orris, G. J. (2013). “Highly-anisotropic elements for acoustic pentamode applications.” Phys- ical Review Letters 111, 024302–024306.
Martin, T. P., Orris, G. J. (2012). “Hybrid inertial method for broadband scattering reduction.” Applied Physics Letters 100, p. 033506.
Miller, D. A. (2006). “On perfect cloaking.” Optics Express 14, 12457–12466. Milton, G. W., Cherkaev, A. V. (1995). “Which elasticity tensors are realiz-
able?” Journal of Engineering Materials Technology 117, 483–493. Nelson, P. A., Elliott, S. J. (1992). Active Control of Sound (Academic Press,
London).
Norris, A., Nagy, A. (2011). “Metal Water: A metamaterial for acoustic
cloaking.” In Proceedings of Phononics 2011, Santa Fe, NM, USA, May
29-June 2. 112–113, Paper Phononics–2011–0037.
Norris, A. N. (2008). “Acoustic cloaking theory.” Proceedings of the Royal
Society A 464, 2411–2434.
Norris, A. N. (2009). “Acoustic metafluids.” Journal of the Acoustical Society
of America 125, 839–849.
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