Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Cooling Microprocessors with Carbon Nanotubes: Technique From Berkeley Lab’s Molecular Foundry Could Also Work with Graphene

Cooling microprocessor chips through the combination of carbon nanotubes and organic molecules as bonding agents is a promising technique for maintaining the performance levels of densely packed, high-speed transistors in the future.
Cooling microprocessor chips through the combination of carbon nanotubes and organic molecules as bonding agents is a promising technique for maintaining the performance levels of densely packed, high-speed transistors in the future.

Abstract:
"Cool it!" That's a prime directive for microprocessor chips and a promising new solution to meeting this imperative is in the offing. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a "process friendly" technique that would enable the cooling of microprocessor chips through carbon nanotubes.

Cooling Microprocessors with Carbon Nanotubes: Technique From Berkeley Lab’s Molecular Foundry Could Also Work with Graphene

Berkeley, CA | Posted on January 22nd, 2014

Frank Ogletree, a physicist with Berkeley Lab's Materials Sciences Division, led a study in which organic molecules were used to form strong covalent bonds between carbon nanotubes and metal surfaces. This improved by six-fold the flow of heat from the metal to the carbon nanotubes, paving the way for faster, more efficient cooling of computer chips. The technique is done through gas vapor or liquid chemistry at low temperatures, making it suitable for the manufacturing of computer chips.

"We've developed covalent bond pathways that work for oxide-forming metals, such as aluminum and silicon, and for more noble metals, such as gold and copper," says Ogletree, who serves as a staff engineer for the Imaging Facility at the Molecular Foundry, a DOE nanoscience center hosted by Berkeley Lab. "In both cases the mechanical adhesion improved so that surface bonds were strong enough to pull a carbon nanotube array off of its growth substrate and significantly improve the transport of heat across the interface."

Ogletree is the corresponding author of a paper describing this research in Nature Communications. The paper is titled "Enhanced Thermal Transport at Covalently Functionalized Carbon Nanotube Array Interfaces." Co-authors are Sumanjeet Kaur, Nachiket Raravikar, Brett Helms and Ravi Prasher.

Overheating is the bane of microprocessors. As transistors heat up, their performance can deteriorate to the point where they no longer function as transistors. With microprocessor chips becoming more densely packed and processing speeds continuing to increase, the overheating problem looms ever larger. The first challenge is to conduct heat out of the chip and onto the circuit board where fans and other techniques can be used for cooling. Carbon nanotubes have demonstrated exceptionally high thermal conductivity but their use for cooling microprocessor chips and other devices has been hampered by high thermal interface resistances in nanostructured systems.

"The thermal conductivity of carbon nanotubes exceeds that of diamond or any other natural material but because carbon nanotubes are so chemically stable, their chemical interactions with most other materials are relatively weak, which makes for high thermal interface resistance," Ogletree says. "Intel came to the Molecular Foundry wanting to improve the performance of carbon nanotubes in devices. Working with Nachiket Raravikar and Ravi Prasher, who were both Intel engineers when the project was initiated, we were able to increase and strengthen the contact between carbon nanotubes and the surfaces of other materials. This reduces thermal resistance and substantially improves heat transport efficiency."

Sumanjeet Kaur, lead author of the Nature Communications paper and an expert on carbon nanotubes, with assistance from co-author and Molecular Foundry chemist Brett Helms, used reactive molecules to bridge the carbon nanotube/metal interface - aminopropyl-trialkoxy-silane (APS) for oxide-forming metals, and cysteamine for noble metals. First vertically aligned carbon nanotube arrays were grown on silicon wafers, and thin films of aluminum or gold were evaporated on glass microscope cover slips. The metal films were then "functionalized" and allowed to bond with the carbon nanotube arrays. Enhanced heat flow was confirmed using a characterization technique developed by Ogletree that allows for interface-specific measurements of heat transport.

"You can think of interface resistance in steady-state heat flow as being an extra amount of distance the heat has to flow through the material," Kaur says. "With carbon nanotubes, thermal interface resistance adds something like 40 microns of distance on each side of the actual carbon nanotube layer. With our technique, we're able to decrease the interface resistance so that the extra distance is around seven microns at each interface."

Although the approach used by Ogletree, Kaur and their colleagues substantially strengthened the contact between a metal and individual carbon nanotubes within an array, a majority of the nanotubes within the array may still fail to connect with the metal. The Berkeley team is now developing a way to improve the density of carbon nanotube/metal contacts. Their technique should also be applicable to single and multi-layer graphene devices, which face the same cooling issues.

"Part of our mission at the Molecular Foundry is to help develop solutions for technology problems posed to us by industrial users that also raise fundamental science questions," Ogletree says. "In developing this technique to address a real-world technology problem, we also created tools that yield new information on fundamental chemistry."

This work was supported by the DOE Office of Science and the Intel Corporation.

####

About Berkeley Lab
The Molecular Foundry is one of five DOE Nanoscale Science Research Centers (NSRCs), national user facilities for interdisciplinary research at the nanoscale, supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize, and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories. For more information about the DOE NSRCs, please visit science.energy.gov/bes/suf/user-facilities/nanoscale-science-research-centers/.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

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

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Laboratories

HP Supercomputer at NREL Garners Top Honor October 19th, 2014

ORNL research reveals unique capabilities of 3-D printing October 15th, 2014

Scientists Map Key Moment in Assembly of DNA-Splitting Molecular Machine: Crucial steps and surprising structures revealed in the genesis of the enzyme that divides the DNA double helix during cell replication October 15th, 2014

NIST researchers enabled by AFM-IR to publish first nanoscale IR spectra of individual plasmonic nanostructures October 10th, 2014

Chemistry

Non-Toxic Nanocatalysts Open New Window for Significant Decrease in Reaction Process October 19th, 2014

QD Vision Wins Prestigious Presidential Green Chemistry Challenge Award from the U.S. Environmental Protection Agency October 16th, 2014

The Körber Foundation congratulates Stefan Hell on winning the 2014 Nobel Prize October 10th, 2014

Physics

Solid nanoparticles can deform like a liquid: Unexpected finding shows tiny particles keep their internal crystal structure while flexing like droplets October 12th, 2014

Unconventional photoconduction in an atomically thin semiconductor: New mechanism of photoconduction could lead to next-generation excitonic devices October 9th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

HP Supercomputer at NREL Garners Top Honor October 19th, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Chip Technology

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

3DXNano™ ESD Carbon Nanotube 3D Printing Filament - optimized for demanding 3D printing applications in the semi-con and electronics industry October 16th, 2014

Nanotubes/Buckyballs

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

NTU develops ultra-fast charging batteries that last 20 years October 14th, 2014

Fast, cheap nanomanufacturing: Arrays of tiny conical tips that eject ionized materials could fabricate nanoscale devices cheaply October 4th, 2014

Discoveries

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Announcements

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

1980s aircraft helps quantum technology take flight October 20th, 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