Navigation Links
UB engineers prove that carbon nanotubes are superior to metals for electronics

BUFFALO, N.Y. -- In the quest to pack ever-smaller electronic devices more densely with integrated circuits, nanotechnology researchers keep running up against some unpleasant truths: higher current density induces electromigration and thermomigration, phenomena that damage metal conductors and produce heat, which leads to premature failure of devices.

But University at Buffalo researchers who study electronics packaging recently made a pleasant discovery: that's not the case with Single-Walled Carbon Nanotubes (SWCNTs).

"Years ago, everyone thought that the problem of cooling for electronics could be solved," said Cemal Basaran, Ph.D., professor in the UB Department of Civil, Structural and Environmental Engineering and director of the Electronics Packaging Lab in UB's School of Engineering and Applied Sciences. "Now we know that's not true. Electronics based on metals have hit a wall. We are done with metals."

Single Walled Carbon Nanotubes are extremely thin, hollow cylinders, measuring no thicker than a single atom. Thousands of times stronger than metals, they are expected to one day replace metals in millions of electronic applications.

Basaran and his doctoral student Tarek Ragab have spent the past four years performing quantum mechanics calculations, which prove that in carbon nanotubes, higher current density does not lead to electromigration and thermomigration; it also produces just one percent of the heat produced by traditional metals, such as copper.

Basaran will present the findings in November when he delivers a keynote lecture at the American Society of Mechanical Engineers (ASME) International Mechanical Engineering Congress and Exposition in Orlando.

The findings demonstrate yet another tantalizing property of CNTs, he said.

"It has been assumed that for carbon nanotubes, the electrical heating process would be governed by Joules law, where resistance in a circuit converts electric energy into heat," said Basaran. "We are the first to show mathematically, from a quantum mechanics point of view, that carbon nanotubes do not follow Joules law."

According to Basaran, this essential difference between metals and carbon nanotubes lies in the way they conduct electricity.

"Even though carbon nanotubes are conductive, they do not have metallic bonds," he said. "As a result, they do not conduct electricity the way that traditional metals do."

In conventional metals, he explained, conduction causes a scattering of electrons within the lattice of the material so that, when electrons move during conduction, they bump into atoms. This creates friction and generates heat, the same way a household iron works.

"On the other hand, in carbon nanotubes, electric conduction happens in a very different, one-dimensional 'ballistic' way," he said. "The electrons are fired straight through the material, so that the electrons have very little interference with the atoms."

He drew an analogy, using the difference between a conventional railroad train and a magnetically levitated train.

"In the conventional train, you have friction between the wheels and the track," said Basaran. "Through the generation of heat, that friction causes a loss of energy. But with a magnetically levitated train, the wheels and track are not in direct contact. Without that friction, they can travel much faster."

The minimal amount of friction gives carbon nanotubes a tremendous advantage over conventional metals, said Basaran. The unique properties of carbon nanotubes will allow engineers to realize a host of smaller, faster and more powerful new devices that right now cannot exist because of the limitations of conventional metals.

"When an electric car finally is manufactured, its batteries probably will be based on carbon nanotubes," said Basaran. "You can't use traditional metals in the engines because they run so hot."

Much of Basaran's $1 million-plus funding at UB comes from sources like the U.S. Navy, which is interested in sophisticated electronics systems that could operate under very demanding conditions, such as the electric ship the Navy is building.

Basaran's unique perspective comes from decades of research, which has fundamentally changed what is known about the high current density performance properties of metals and their limitations.

He also sounded a cautionary note, pointing out that current research and development expenditures on carbon nanotubes in the U.S. electronics industry are very small when compared to those of our Asian competitors.

"If the industry continues this way, when carbon nanotube-based electronics become a reality, U.S. electronics manufacturers may be in a position similar to U.S. car manufacturers today, because they have failed to keep up with advances in engineering," he said.


Contact: Ellen Goldbaum
716-645-5000 x1415
University at Buffalo

Related biology technology :

1. Engineers tune a nanoscale grating structure to trap and release a variety of light waves
2. New Educational Website Celebrates the Accomplishments of Engineers
3. Virginia Tech engineers investigate energy independent monitoring system for bridges
4. Techstreet Launches BuildingBlocks Utility for Industry Standards Saving Time and Increasing Productivity for Engineers
5. Virginia Tech engineers identify conditions that initiate erosion
6. Engineers aim to solve burning computer problem
7. NC State engineers discover nanoparticles can break on through
8. Online Systems Engineering Master's Program Attracts Engineers from Fortune 500 Firms
9. Virtual world is sign of future for scientists, engineers
10. Using a grating with a grade, engineers trap a rainbow
11. University of Pennsylvania engineers reveal what makes diamonds slippery at the nanoscale
Post Your Comments:
(Date:11/30/2015)... Florida , November 30, 2015 ... specializing in the development of innovative peptide and gene-based ... metastatic disease, today announced it will be presenting at ... on December 1, 2015 at 2.30 PM PT. Dr. ... and Strategic Advisor will be giving the presentation and ...
(Date:11/30/2015)... 2015  Aytu BioScience, Inc. (OTCQB: AYTU), a commercial-stage ... will present at two upcoming investor conferences. Aytu is ... virtual conference, to be held December 3, 2015, and ... held December 2 nd & 3 rd , ... streamed live via webcast. Josh Disbrow , ...
(Date:11/30/2015)... RATON, Florida and MAGDEBURG, Germany ... Congress of NeuroRehabilitation (ECNR) in Vienna, Austria ... 3rd European Congress of NeuroRehabilitation (ECNR) in ... 2015. --> NovaVision, a wholly owned subsidiary of ... the European version of its Internet-delivered NovaVision Therapy Suite at ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... integration with MarkLogic, the Enterprise NoSQL database platform provider, creating a seamless ... , Smartlogic’s Content Intelligence capabilities provide a robust set of semantic tools ...
Breaking Biology Technology:
(Date:11/19/2015)... -- Although some 350 companies are actively involved in molecular ... according to Kalorama Information. These include Roche Diagnostics, Hologic, Abbott ... of the 6.1 billion-dollar molecular testing market, according to ... Diagnostic s .    ... one company and only a handful of companies can ...
(Date:11/17/2015)... 17, 2015 Paris from ... --> Paris from 17 th until ... biometrics innovation leader, has invented the first combined scanner in ... same scanning surface. Until now two different scanners were required: ... can capture both on the same surface. This innovation ...
(Date:11/17/2015)... EASTON, Mass. , Nov. 17, 2015 ... a leader in the development and sale of broadly ... the worldwide life sciences industry, today announced it has ... of its $5 million Private Placement (the "Offering"), increasing ... to $4,025,000.  One or more additional closings are expected ...
Breaking Biology News(10 mins):