Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Nanotubes find niche in electric switches

Abstract:
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.

Nanotubes find niche in electric switches

Houston, TX | Posted on March 16th, 2009

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.

Co-authors on the paper also included Geza Toth, Jani Mäklin, Niina Halonen, Jaakko Palosaari, Jari Juuti and Heli Jantunen, all of the University of Oulu, and Gregory Sawyer of the University of Florida.

Support for the research was provided by the Academy of Finland, the University of Oulu's Micro and Nanotechnology Center, the Air Force Office of Scientific Research and the Semiconductor Research Corporation.

####

About Rice University
Located in Houston, Rice University is consistently ranked one of America's best teaching and research universities. Known for its "unconventional wisdom," Rice is distinguished by its: size -- 3,001 undergraduates and 2,144 graduate students; selectivity -- 12 applicants for each place in the freshman class; resources -- an undergraduate student-to-faculty ratio of 5-to-1; sixth largest endowment per student among American private research universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work.

Contacts:
Jade Boyd
Associate Director and Science Editor
Office of Public Affairs/News & Media Relations
Rice University
(office) 713-348-6778
(cell) 713-302-2447

www.rice.edu

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

New method in the fight against forever chemicals September 13th, 2024

Energy transmission in quantum field theory requires information September 13th, 2024

Breakthrough in proton barrier films using pore-free graphene oxide: Kumamoto University researchers achieve new milestone in advanced coating technologies September 13th, 2024

Quantum researchers cause controlled ‘wobble’ in the nucleus of a single atom September 13th, 2024

Nanotubes/Buckyballs/Fullerenes/Nanorods/Nanostrings

Catalytic combo converts CO2 to solid carbon nanofibers: Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material January 12th, 2024

TU Delft researchers discover new ultra strong material for microchip sensors: A material that doesn't just rival the strength of diamonds and graphene, but boasts a yield strength 10 times greater than Kevlar, renowned for its use in bulletproof vests November 3rd, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Detection of bacteria and viruses with fluorescent nanotubes July 21st, 2023

Announcements

Giving batteries a longer life with the Advanced Photon Source: New research uncovers a hydrogen-centered mechanism that triggers degradation in the lithium-ion batteries that power electric vehicles September 13th, 2024

NYU Abu Dhabi researchers develop novel covalent organic frameworks for precise cancer treatment delivery: NYU Abu Dhabi researchers develop novel covalent organic frameworks for precise cancer treatment delivery September 13th, 2024

New discovery aims to improve the design of microelectronic devices September 13th, 2024

New method in the fight against forever chemicals September 13th, 2024

Energy

Unveiling the power of hot carriers in plasmonic nanostructures August 16th, 2024

Groundbreaking precision in single-molecule optoelectronics August 16th, 2024

Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024

Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project