Nanotubes: Knot just for miniature work

Individual carbon nanotubes are too small to see without a powerful microscope. A new technique, however, can spin carbon nanotubes into ribbons and threads visible to the naked eye.

Designers might someday use the superstrong fibers—which they can bend and even tie into knots—to make tough but lightweight composite materials, energy-converting devices, and new generations of electric cables, says Philippe Poulin of the Paul Pascal Research Center in Pessac, France.

In the spinning process, Poulin and his colleagues report in the Nov. 17 Science, they first dispersed single-walled carbon nanotubes in water. Then, the team injects this fluid from a syringe into a polymer-containing solution, a process that causes the nanotubes to aggregate and align.

Ray H. Baughman of Honeywell International in Morristown, N.J., and his colleagues have attempted to improve the spinning process by using especially pure carbon nanotubes made with a new technique called the high-pressure carbon monoxide process. One goal for Baughman’s group is to use these nanotube fibers to make artificial muscles.