Page 40 - ASME IMECE 2015 Program

Track Plenary

the past year, Sandeep has been engaged in a new product development simple construct may also open broad application potentials when
in medical technology, continuing his intertwining of pushing the boundar- combined with existing technologies.
ies of CAE performance and entrepreneurial spirit in the new realization of
novel technologies. The hybrid resonances can also be shown to exist for the electromagnetic
waves. Hence, total microwave absorption is entirely feasible at tunable
frequencies. In that case, the so-called perfect magnetic boundary
condition is realized in an interesting fashion that is analogous to the
Track 16: Vibration, Acoustics & Wave Propagation manifestations of the acoustic hybrid resonance.
SESSION 16-2-1: RECENT ADVANCES IN PHONONIC CRYSTALS
AND METAMATERIALS I 1. Physical Review Letters, vol. 101, 204301 (2008).
Wednesday, November 18, 10:30am–12:00pm 2. Nature Communications, vol. 3, p. 756 (2012).
372E, Convention Center 3. Nature Materials, vol. 13, p. 873 (2014).
Hybrid Resonance and the Realization of Point Acoustic Sink
*Work done in collaboration with Guancong Ma, Min Yang, Songwen Xiao,
(IMECE2015-50222)
and Zhiyu Yang.
Ping Sheng
Hong Kong University of Science & Technology
Track 19: Advances in Multidisciplinary Engineering
Abstract: Traditional means of acoustic absorption generally make use of SESSION 19-1-1: PLENARY SESSION
porous and fibrous materials, gradient index structures, or perforated Tuesday, November 17, 1:15pm–2:45pm
panels with tuned cavity depth behind the panels. They usually result in 380B, Convention Center
either imperfect impedance matching to the incoming wave or very bulky
structures with dimensions comparable to the wavelength. This state of Multidisciplinary Engineering and Education
affairs is dictated by the intrinsic low absorption coefficient of almost all (IMECE2015-54148)
the materials in the acoustic frequency range.
Mary Boyce
In this talk, I will first introduce the decorated membrane resonator (DMR), Columbia University
comprising a 200 micron thick latex rubber membrane decorated by small
Abstract: Overview of Multidisciplinary Engineering and Education and
platelet(s), each on the order of 1 gram in mass. In the simplest case of one
Professor Suh’s contribution.
circular button at the center of a circular membrane, the DMR has multiple
resonances, the first two usually <1 kHz. Between the two eigenmodes,
Biography: Dean of Engineering at Columbia University
there is an anti-resonance at which the dynamic effective mass displays a
resonant dispersion and the DMR can totally reflect the incoming wave [1].
These DMRs can be very effective sound absorbers [2,3]. By placing a
DMR with deep-subwavelength transverse dimensions close to a hard Nam Pyo Suh: A Model for Multidisciplinary Engineering
reflecting surface, separated by a thin cell of sealed gas, the two lowest (IMECE2015-54149)
resonances would be hybridized to create a new resonance at a frequency Charles Tucker
close to the anti-resonant frequency. The hybridized resonance can have
University of Illinois at Urbana-Champaign
two useful degrees of freedom, as its vibrational profile must be a linear
combination of the eigenfunctions from the two original resonances.
Abstract: As our world grows increasingly complex, the most important
These two degrees of freedom are manifested as the average and
technological problems consistently transcend the boundaries of
variance of its (spatially varying) displacement normal to the membrane.
traditional engineering disciplines. Addressing these grand-challenge
Whereas the variance component is decoupled from the radiation modes,
issues requires a special type of engineer, one who can draw deeply from
that is, deaf, and serves the absorption functionality, the average
multiple disciplines, think creatively, and foster new ways of thinking in
displacement component can be tuned to impedance-match with the
individuals and organizations. Nam Pyo Suh is one such person, and he
background medium. The net result is a perfect acoustic absorber at a
serves as a model for what a multidisciplinary engineer can and should be.
frequency that is tunable by varying either the weight of the button or the
In his technical career, he made important contributions to multiple
thickness of the gas cell. By utilizing the very large displacement of the
disciplinary areas, including manufacturing, tribology, polymer processing,
membrane, we have also realized the acoustic-electrical power conver-
and design theory. His publications in each of these areas have been cited
sion with a high efficiency of 23% [3].
thousands of times, and he had more than 40 publications that have been
cited more than 100 times. He also fostered new ways of educating
The deep subwavelength scale of the hybrid resonant unit cells makes
engineering students, as a department head at MIT and as president of
each cell essentially a point acoustic sink, the counterpart to a point
KAIST. As an assistant director for engineering at NSF, he shifted the
source, time-reversed. It’s very narrow but tunable total absorption
culture of academic research in the U.S., promoting more collaboration
bandwidth may also be advantageous in frequency-selective applications
with corporations and greater responsiveness to the needs of industry by
like filters, sensors, and transducers. Extension of the concept to acoustic
40 waves in other fluid media should be straightforward and may lead to creating Engineering Research Centers. This talk will review important
scientific and technological contributions from Professor Suh, including the
applications in ultrasonics, hydroacoustics, and weak sound detection. It’s
delamination theory of wear, the creation of commercial processes for