Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Scientists use molecular layers to study nanoscale heat transfer

Abstract:
Scientific research has provided us with a fundamental understanding of how light (via photons) and electricity (via electrons) move within and between materials at the micrometer or nanometer levels, making possible a wide variety of miniature devices such as transistors, optical sensors and microelectromechanical systems (MEMS). However, man's knowledge of micro- and nanoscale heat flow is rudimentary at best. Now, a research team at the University of Illinois at Urbana-Champaign (UIUC) has developed a novel system for examining and measuring nanoscale thermal conductance at the interface between two materials. With further refinement, the scientists believe their advance may one day provide data for applications such as harvesting electricity from waste heat, better cooling of microelectronic devices and "heat-seeking" targeting of disease cells by hyperthermal (above normal body temperature) therapeutics.

Scientists use molecular layers to study nanoscale heat transfer

College Park, MD | Posted on October 28th, 2012

The team's findings will be presented by Mark Losego, formerly a post-doctoral fellow at UIUC and now a research assistant professor in chemical and biomolecular engineering at North Carolina State University, during the AVS 59th International Symposium and Exhibition, held Oct. 28-Nov. 2, 2012, in Tampa, Fla.

At the nanoscale, thermal properties are the result of vibrations between neighboring atoms. Bonds between atoms carry these vibrations similar to an oscillating spring. The UIUC team developed a technique for studying the effects of these bonds on heat transport across an interface between two different materials. "We wanted a system where we could observe, analyze and quantify thermal flow across an interface with atomic-level precision," Losego says.

The system starts with a substrate base of quartz crystal, upon which the researchers place molecular chains that are 12 carbon atoms long. At the base of each chain is a chemical "cap" that covalently bonds to quartz. The attraction of these caps to the substrate spontaneously aligns all of the carbon chains into an ordered array of molecules known as a self-assembled monolayer (SAM). At the opposite end of each carbon chain is a different kind of cap, either a thiol (sulfur and hydrogen) group that bonds strongly to metals or a methyl group (carbon and hydrogen) that bonds weakly.

"We then make use of a viscoelastic silicone stamp to 'transfer print' gold layers onto the SAM surface," Losego explains. "This process is similar to transferring a decal onto a T-shirt where the gold film is the 'decal' attached to the silicone stamp 'backing'. When we slowly peel away the silicone, we leave the gold layer on top of the SAM."

It is at the interface between the gold film and the SAM, Losego says, where nanoscale heat flow is characterized. "Changing the chemical groups that are in contact with the gold layer allows us to see how different bonds affect heat transfer," he adds.

Combined with an ultrafast laser technique capable of monitoring temperature decay (or heat loss) with picosecond (trillionth of a second) resolution, the UIUC researchers are able to use their experimental system to evaluate heat flow at the atomic scale. "We heat the gold layer attached to the monolayer and can monitor temperature decay with time," Losego explains. "Concurrently, we observe oscillations in the gold film that indicate the strength of the bonds at the gold-SAM junction. Using these measurements we are able to independently verify that strong bonds [fast-decaying oscillations] have rapid heat transfer while weak bonds [slowly decaying oscillations] have slower heat transfer."

The researchers plan to refine their nanoscale thermal measurement system and develop theoretical calculations to better interpret the data it produces.

MORE INFORMATION ABOUT THE AVS 59th INTERNATIONAL SYMPOSIUM & EXHIBITION

The Tampa Convention Center is located along the Riverwalk in the heart of downtown Tampa at 333 S. Franklin St., Tampa, Florida, 33602.

ABOUT AVS

Founded in 1953, AVS is a not-for-profit professional society that promotes communication between academia, government laboratories, and industry for the purpose of sharing research and development findings over a broad range of technologically relevant topics. Its symposia and journals provide an important forum for the dissemination of information in many areas of science and technology, enabling a critical gateway for the rapid insertion of scientific breakthroughs into manufacturing realities.

####

For more information, please click here

Contacts:
Catherine Meyers
301-209-3088

Copyright © American Institute of Physics (AIP)

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 Links

Main meeting website:

Technical Program:

Housing and Travel Information:

Related News Press

Physics

Solid state physics: Quantum matter stuck in unrest August 1st, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Detecting small metallic contaminants in food via magnetization: A practical metallic-contaminant detecting system using three high-Tc RF superconducting quantum interference devices (SQUIDs) July 29th, 2015

News and information

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Harris & Harris Group Portfolio Company, HZO, Announces Partnerships with Dell and Motorola August 1st, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Kalam: versatility personified August 1st, 2015

Chemistry

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Nanomedicine

Gold-diamond nanodevice for hyperlocalised cancer therapy: Gold nanorods can be used as remote controlled nanoheaters delivering the right amount of thermal treatment to cancer cells, thanks to diamond nanocrystals used as temperature sensors August 1st, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Take a trip through the brain July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Discoveries

Gold-diamond nanodevice for hyperlocalised cancer therapy: Gold nanorods can be used as remote controlled nanoheaters delivering the right amount of thermal treatment to cancer cells, thanks to diamond nanocrystals used as temperature sensors August 1st, 2015

Shaping the hilly landscapes of a semi-conductor nanoworld August 1st, 2015

Solid state physics: Quantum matter stuck in unrest August 1st, 2015

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Announcements

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Harris & Harris Group Portfolio Company, HZO, Announces Partnerships with Dell and Motorola August 1st, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Events/Classes

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Pakistani Students Who Survived Terror Attack to Attend Weeklong “NanoDiscovery Institute” at SUNY Poly CNSE in Albany July 29th, 2015

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Nanometrics Announces Upcoming Investor Events July 28th, 2015

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