Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotubes find niche in electric switches

12.03.2009
Study finds nanotube structures could improve electric motors

New research from Rice University and the University of Oulu in Oulu, Finland, finds that carbon nanotubes could significantly improve the performance of electrical commutators that are common in electric motors and generators.

The research, which appeared online this month in the journal Advanced Materials, finds that "brush contact" pads made of carbon nanotubes had 10 times less resistance than did the carbon-copper composite brushes commonly used today. Brush contacts are an integral part of "commutators," or spinning electrical switches used in many battery-powered electrical devices, such as cordless drills.

"The findings show that nanotubes have a great deal of practical relevance as brush contacts," said lead researcher Pulickel Ajayan, Rice's Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science. "The technology is widely used in industry, both in consumer gadgets as well as larger electrical machinery, so this could be a very interesting, near-term application for nanotubes." The combination of mechanical and electrical properties of nanotubes makes this possible.

The carbon nanotubes used in the study are hollow tubes of pure carbon that are about 30 nanometers in diameter. By comparison, a human hair is about 100,000 nanometers in diameter. In addition to being small, nanotubes are also extremely lightweight and durable, and they are excellent conductors of heat and electricity.

Because of these properties, the researchers decided to test nanotubes as brush contacts. Brush contacts are conducting pads held against a spinning metal disc or rod by spring-loaded arms. Current is passed from the spinning disc through the brush contacts to other parts of the device.

To test the feasibility of using carbon nanotube brush contacts, the research team replaced the ordinary copper-carbon composite brushes of an electric motor with small blocks that contain millions of carbon nanotubes. Under an electron microscope, these millimeter-square blocks look like a tightly packed forest.

From Ajayan's previous work, the team knew that these nanotube forests react something like a "memory foam" pillow; they regain their shape very quickly after they are compressed.

"This elasticity is something that's not found in existing composites that are used for brush contacts, and that's the essence of why the nanotube brush contacts perform better: They keep much more of their surface area in contact with the spinning disc," said Robert Vajtai, faculty fellow at Rice. Vajtai worked on the study with Ajayan and a group of researchers in Finland led by University of Oulu Researcher Krisztian Kordas.

The team believes that the improved contact between the surface of the spinning disc and the brush accounts for the 90 percent reduction in lost energy.

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Materials Sciences:

nachricht Serendipity uncovers borophene's potential
23.02.2017 | Northwestern University

nachricht Switched-on DNA
20.02.2017 | Arizona State University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>