goodwill559
Inspired
I read that Cliff was involved with Navy projects related to sonar, so he probably already knows about this line of research, but I thought I'd share.
*Scientists are now publishing findings related to 'acoustic cloaking,' or the masking of objects from sound waves or sonar detection. Details have been shared in Physical Review Letters.
Shu Zhang, Chunguang Xia, and Nicholas Fang*
Department of Mechanical Science & Engineering and the Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana-Champaign, Illinois 61801, USA
Received 12 September 2010; revised 9 November 2010; published 10 January 2011
See accompanying Viewpoint: Physics - Invisibility cloak for ultrasonic waves
Invisibility devices based on coordinate transformation have opened up a new field of considerable interest. We present here the first practical realization of a low-loss and broadband acoustic cloak for underwater ultrasound. This metamaterial cloak is constructed with a network of acoustic circuit elements, namely, serial inductors and shunt capacitors. Our experiment clearly shows that the acoustic cloak can effectively bend the ultrasound waves around the hidden object, with reduced scattering and shadow. Because of the nonresonant nature of the building elements, this low-loss (∼6 dB/m) cylindrical cloak exhibits invisibility over a broad frequency range from 52 to 64 kHz. Furthermore, our experimental study indicates that this design approach should be scalable to different acoustic frequencies and offers the possibility for a variety of devices based on coordinate transformation.
© 2011 The American Physical Society
URL:
Phys. Rev. Lett. 106, 024301 (2011): Broadband Acoustic Cloak for Ultrasound Waves
DOI:
10.1103/PhysRevLett.106.024301
PACS:
43.20.+g, 43.35.+d, 46.40.Ff
*Scientists are now publishing findings related to 'acoustic cloaking,' or the masking of objects from sound waves or sonar detection. Details have been shared in Physical Review Letters.
Shu Zhang, Chunguang Xia, and Nicholas Fang*
Department of Mechanical Science & Engineering and the Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana-Champaign, Illinois 61801, USA
See accompanying Viewpoint: Physics - Invisibility cloak for ultrasonic waves
Invisibility devices based on coordinate transformation have opened up a new field of considerable interest. We present here the first practical realization of a low-loss and broadband acoustic cloak for underwater ultrasound. This metamaterial cloak is constructed with a network of acoustic circuit elements, namely, serial inductors and shunt capacitors. Our experiment clearly shows that the acoustic cloak can effectively bend the ultrasound waves around the hidden object, with reduced scattering and shadow. Because of the nonresonant nature of the building elements, this low-loss (∼6 dB/m) cylindrical cloak exhibits invisibility over a broad frequency range from 52 to 64 kHz. Furthermore, our experimental study indicates that this design approach should be scalable to different acoustic frequencies and offers the possibility for a variety of devices based on coordinate transformation.
© 2011 The American Physical Society
URL:
Phys. Rev. Lett. 106, 024301 (2011): Broadband Acoustic Cloak for Ultrasound Waves
DOI:
10.1103/PhysRevLett.106.024301
PACS:
43.20.+g, 43.35.+d, 46.40.Ff
