Researchers at Duke University have succeeded in growing one atom thick carbon nanotubes, 100 times longer than usual. They have also been able to grow these nanotubes with controlled straightness and orientation.
Their discovery overcomes a major hurdle to the use of nanotubes in tiny nanoelectronic devices. Further to this, they have also successfully grown checkerboard like grids of nanotubes which could form the basis of nanoelectronic devices.
The researchers grew the nanotubes from tiny catalytic clusters of iron and molybdenum atoms dotted onto a small rectangle of silicon inside a quartz tube. The nanotubes continued to grow along the silicon surface in the same direction of flow as the feed gas of carbon monoxide and hydrogen. These gases were rapidly heated to 900°C, a temperature that would melt normal glass.
Their finding were published in the Journal of the American Chemical Society. At the time of publishing, they believed that their nanotubes were the longest recorded, with lengths as long as 4mm having been produced.
They were also able to grow interconnecting grids by growing nanotubes in a perpendicular direction using suitably flowing gases. These structures could potentially form the basis of nanoelectronic circuitry. Furthermore, the long nanotubes could make the evaporation of multiple metal electrodes on a single nanotube quite simple, allowing multiple devices to be created on the same nanotube.