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Roozbeh Ghaffari and Michael Vahey Named Recipients
of 2008 Peake Research Prizes
For Immediate Release
THURSDAY, 1 May 2008
Contact: William Smith, Assistant
Director for Finance and Sponsor Relations
Phone: +1.617.253.5621
Email: whs@mit.edu
CAMBRIDGE, MA. 05.01.2008
The Research Laboratory of Electronics (RLE) at the
Massachusetts Institute of Technology (MIT) announces
that Dr. Roozbeh Ghaffari and Mr. Michael Vahey have
won Helen Carr Peake Research Prizes for 2008.
Dr. Ghaffari is a February 2008 graduate of the Speech
and Hearing Bioscience and Technology (SHBT) Program
in the Division of Health Sciences and Technology (HST).
His doctoral dissertation was supervised by Professor
Dennis M.
Freeman of RLE.
Dr. Ghaffari's research addressed the behavior of
the tectorial membrane, which is a microscopic gelatinous
structure in the inner ear whose role in hearing is
not well understood. It has long been known that sound
produces traveling waves along the inner ear's basilar
membrane that are sorted by frequency in the propagation
process and excite the sensory hair cells which transmit
sound to the brain. However, existing models of the
inner ear are unable to account for the enormous amplification
that occurs in this process. Through nano-scale measurements,
which required an entirely new class of measurement
tools, Dr. Ghaffari demonstrated that sound induces
longitudinally-propagating traveling waves in a tectorial
membrane segment that was suspended between a fixed
and a movable support. This hitherto unobserved phenomenon,
which was reported in Proceedings of the National Academy
of Science, might help explain the ear's extraordinary
spectral tuning and amplification. Moreover, this work
could affect the design of hearing aids and cochlear
implants, and it has implications for inherited forms
of hearing loss that affect the tectorial membrane.
Mr. Vahey is a doctoral student in the MIT Department
of Electrical Engineering and Computer Science (EECS)
whose research is being supervised by Professor Joel
Voldman in RLE.
Mr. Vahey's doctoral research has led to a new microscale
separation technique that sorts cells based upon their
apparent electrical conductivity. Whereas standard
separations based on dielectrophoresis suffer from
effects due to variations in cell size, Mr. Vahey's
work, called iso-dielectric separation, avoids such
problems by placing cells into a conductivity gradient
in which they migrate until they reach the position
at which their net polarization vanishes. Although
conceptually simple, Mr. Vahey did careful analysis
and numerical modeling to circumvent constraints and
avoid the instabilities that prevented this technique
from being demonstrated previously. With his devices,
Mr. Vahey has successfully performed separations of
both model particles and cells based upon a phenotypic
marker. His research, which was just published in Analytical
Chemistry, has broad implications for both biotechnology
and medicine. For example, useful biological differences
can manifest themselves as differences in electrical
conductivity so that Mr. Vahey's approach could then
be used to reliably isolate the abnormal cells.
The selections of the award recipients were made by
a committee consisting of Professor Freeman (MIT/RLE),
Professor Jeffrey H. Shapiro (MIT, Director RLE), Professor
M. Charles Liberman (Harvard, Director EPL), Professor
William T. Peake (MIT/RLE/EPL) and Professor John L.
Wyatt (MIT/RLE).
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