Nanotubes grown on plastic

Researchers from the University of Cambridge in England have devised a way to grow vertical forests of carbon nanotubes on flexible plastic.

The combination of nanoscale electronic components and a plastic substrate could enable applications ranging from flexible electronics like wearable computer displays to new types of fuel cells, according to the researchers.

Carbon nanotubes are rolled-up sheets of carbon atoms. The researchers' nanotubes ranged from 20 to 50 nanometers in diameter, which is less than one thousandth the diameter of the human hair. Nanotubes have useful electronic properties and can be used to form transistors, the building blocks of computer circuits.

Other methods of combining nanotubes and plastic films involve forming films over existing nanotubes. The researchers' technique allows them to grow positioned, vertical nanotubes on a plastic film. Vertical nanowires are particularly useful for making electric field emitters, which can be used in an emerging type of flat-screen display.

Key to the researchers' approach was finding a way to grow nanotubes that proved cool enough for the plastic to tolerate. The researchers grew lines and dots of free-standing nanotubes onto chromium-covered polyamide foil, and were able to cover large areas of the substrate without degrading or bending the material.

It's not possible to tell how soon practical applications could be available, according to the researchers. The work appeared in the December 1, 2003 issue of Applied Physics Letters.