Abstracts

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MIT Sea Grant College Program Special Seminar
Friday, October 23rd
E38-3rd Floor Conference Room
12:00 – 1:00pm

*Teaching Old Waves New Tricks: The Quest For Acoustic Meta-Materials*

*Dr. Nicholas X. Fang*
Department of Mechanical Engineering,
Massachusetts Institute of Technology
nicfang@mit.edu

For centuries we enjoyed light and sound as tools to manipulate, store and control the flow of information and energy. However, our need to transmit information and energy through these wave channels suffered a physical limit dictated by diffraction. For example, Young’s double slit experiments suggest that for an observer at a distance away from the two slits, one cannot distinguish these slits from one when the gap of these slits are close to wavelength of light. Can we overcome the diffraction limit by bending and folding waves, in a similar fashion to paper origami?

In this talk, I will present our efforts to 3D acoustic metamaterials with tailored wavefront and energy flow, which shows promise on focusing and rerouting ultrasound waves and phonons at unprecedented precision. For example, complementary metamaterials for ultrasonic imaging has been investigated, enabling effective cancellation of the aberration layer. Further, sound propagation in a chain of Helmholtz resonators has been studied theoretically through a nonlocal theory which captures the effects due to the spatial dispersion. These theoretical and experimental studies facilitated design of compact and broadband phase shifters. The potential application of such novel device concept in underwater communication and medical ultrasound will be also discussed.

*Nicholas X. Fang received his BS and MS in physics from Nanjing University, and his PhD in mechanical engineering from University of California Los Angeles. He arrived at MIT in Jan 2011 as Associate Professor of Mechanical Engineering. Prior to MIT, he worked as an assistant professor at the University of Illinois Urbana-Champaign. Professor Fang’s areas of research look at nanophotonics and nanofabrication. His recognitions include the ASME Chao and Trigger Young Manufacturing Engineer Award (2013); the ICO prize from the International Commission of Optics (2011); an invited participant of the Frontiers of Engineering Conference by National Academies in 2010; the NSF CAREER Award (2009) and MIT Technology Review Magazine’s 35 Young Innovators Award (2008).*

We encourage attendees to bring their lunch to the seminar. The seminar is open, please pass this message along to interested parties. Questions can be sent to KBaltes@mit.edu.

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Communication Specialist, MIT Sea Grant
Massachusetts Institute of Technology
77 Massachusetts Ave E38 - 762B
Cambridge, MA 02139
617.253.3461 I kbaltes@mit.edu
http://seagrant.mit.edu