Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > While supporting others' research, CNF's Derek Stewart pursues his own in nanoscale heat transfer

Jason Koski/University Photography
CNF computational research associate Derek Stewart stands in front of the CNF computer cluster in Rhodes Hall. His research in nanoscale heat transfer may someday allow such server farms to have cooling systems without fans.
Jason Koski/University Photography
CNF computational research associate Derek Stewart stands in front of the CNF computer cluster in Rhodes Hall. His research in nanoscale heat transfer may someday allow such server farms to have cooling systems without fans.

Abstract:
Walk into a roomful of high-performance computer servers, and it's hard to hear over the din of fans -- the only things keeping the servers, consuming thousands of watts of power, from overheating.

Wouldn't it be cool if computers didn't overheat?

Quick dissipation of heat at the smallest, most fundamental scales of electronic devices is just one way that the work of Derek Stewart may someday change the face of computing and other electronics.

While supporting others' research, CNF's Derek Stewart pursues his own in nanoscale heat transfer

ITHACA, NY | Posted on December 23rd, 2008

"Instead of using fans to blow air across and take that energy and move it away, you can actually do something on the surface of your system to cool it down," said Stewart, computational research associate at the Cornell NanoScale Science and Technology Facility (CNF).

His primary responsibility is supporting CNF users with his expertise in computational modeling. He takes publicly available computational codes for such things as calculating electronic properties of materials or microfluidic flows of various devices and makes them accessible to CNF's worldwide users. But beyond that, he hopes his own research in the area of nanoscale heat transfer may lead to unique codes that other researchers could also use.

Stewart's expertise complements CNF's nanofabrication capabilities by allowing users to model devices before they build them, or to understand why their devices behave like they do, explained George Malliaras, the Lester B. Knight Director of CNF. To keep them current in their fields, research associates are also encouraged to pursue their own research, Malliaras said.

Since 2005, CNF users have been able to perform large-scale simulations and computations to accompany their physical experimentation in the lab, thanks to a cluster of 56 dual-processor computer nodes. Stewart, as manager of this network, supports researchers by helping them modify existing codes, as well as come up with new ones.

As someone who tries to understand atomic principles by modeling them, Stewart works in a research world that is largely theoretical. But learning how materials transfer heat on the nanoscale, he explained, can then lead to understanding of the best materials and methods to use. Current computational models of thermal conductivity are still crude, according to Stewart, in part because it is difficult to map the scattering of heat across phonons -- lattice vibrations of atoms -- which carry heat.

Stewart has been using an approach called density functional theory to determine the relationship between atoms in materials as well as what causes phonon scattering. By putting these terms in a larger-scale computer model, he has been able to predict the thermal conductivity of silicon and germanium, which are widely used in the semiconductor industry.

Stewart has also contributed to collaborative research that shows carbon nanotubes, which are super-strong cylindrical carbon molecules, hold great promise for nanoscale heat transfer because the strong bonds between carbon atoms lead to a very high thermal conductivity. But what happens when a nanotube isn't perfect? Stewart and researchers from Boston College, University of Regensburg and CEA-Grenoble have set out to answer that by examining how impurities and defects in carbon nanotubes reduce thermal conductivity.

The ideal situation is to have phonons transmit as much heat as possible away from the circuit or whatever the device might be. The researchers found that heat transfer through a nanotube can be dramatically reduced by locally distorting its symmetry.

Stewart, who came to Cornell in 2004 after a postdoctoral fellowship at Sandia National Laboratories in California, said he was attracted to the idea of pursuing research that would also support other researchers at CNF.

"It makes me focus not just on research at Cornell, but also on drawing people in from other institutions to make sure they get research done here," he said.

People interested in doing simulation work at CNF or learning more about Stewart's research can visit http://www.nnin.org/nnin_compsim.html or contact him directly at

####

For more information, please click here

Contacts:
Anne Ju
(607) 255-9735


Media Contact:
Blaine Friedlander
(607) 254-8093

Copyright © Cornell University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014

President Obama Meets U.S. Laureates of 2014 Kavli Prizes August 1st, 2014

Stanford researchers seek 'Holy Grail' in battery design: Pure lithium anode closer to reality with development of protective layer of interconnected carbon domes August 1st, 2014

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

Chip Technology

Pressure probing potential photoelectronic manufacturing compound July 31st, 2014

Nanometrics Reports Second Quarter 2014 Financial Results July 30th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Discoveries

Iranian Scientists Produce Cobalt–Alumina Ceramic Nano Inks August 1st, 2014

Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014

Taking the guesswork out of cancer therapy: New molecular test kit predicts patient’s survival and drug response August 1st, 2014

Carnegie Mellon Chemists Create Nanofibers Using Unprecedented New Method July 31st, 2014

Announcements

Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014

President Obama Meets U.S. Laureates of 2014 Kavli Prizes August 1st, 2014

Stanford researchers seek 'Holy Grail' in battery design: Pure lithium anode closer to reality with development of protective layer of interconnected carbon domes August 1st, 2014

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE