Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UB Engineers Prove That Carbon Nanotubes Are Superior to Metals for Electronics

24.03.2009
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.

Basaran and his colleagues in the Electronics Packaging Lab actively participate in the UB 2020 strategic strength in Integrated Nanostructured Systems, which brings together physicists and engineers to further enhance and understand nanotechnologies like carbon nanotubes.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.

Ellen Goldbaum | EurekAlert!
Further information:
http://www.buffalo.edu

More articles from Power and Electrical Engineering:

nachricht Did you know that the wrapping of Easter eggs benefits from specialty light sources?
13.04.2017 | Heraeus Noblelight GmbH

nachricht To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
05.04.2017 | Carnegie Institution for Science

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>