Carbon nanotubes used to create tiny clutches

01 June 2012

Posted by John Bull

A new breakthrough in the field of nanotechnology and robotics has been unveiled by experts in China who have created tiny clutches.

The scientists from a number of Chinese institutions used carbon nanotubes separated by a film of water to assemble the devices and have tested simulations of them.

Made from just two concentric nanotubes, the speed regulation solution is controlled by electrowetting forces and the friction between the water and their inner and outer walls.

Writing in the Journal of Applied Physics, the team revealed the tiny devices can deliver stepless regulation of speed by altering the magnitude of charge sent to the nanotubes.

The device is engaged and disengaged using electrical charges and the researchers have said it could be used in the future to construct nanorobots, although they stressed further research is required.

Carbon nanotubes have also been employed by researchers from Stanford University in the US to improve catalysts in fuel cells.

They have developed a technique that allows multi-walled concentric nanotubes to be used as a low-cost alternative to platinum for fuel cells and metal-air battery catalysts.

Reducing the price of catalysts, which are used within fuel cells to create electricity, could provide a way of creating new products for large-scale commercialization.

Reporting in the journal Nature Nanotechnology, Stanford Professor of Chemistry, Yanguang Li, Lead Author of the study, stated: "A typical carbon nanotube has few defects. But defects are actually important to promote the formation of catalytic sites and to render the nanotube very active for catalytic reactions."

Adding impurities to the outer wall was found to make it more active for catalytic reactions and he explained using concentric nanotubes enhanced electrical conductivity, speeding up chemical reactions in hydrogen or metal-air cells.

Samples have been sent to fuel cell specialists for trials and the breakthrough could lead to the creation of high-density fuel sources.