Is There Anything Carbon Can't Do?

It's another Tech Tuesday!

As the price of copper has been rising, researchers have been looking for a replacement that is less expensive but would have the conductivity of the copper it would replace.

For some applications, the use of fiber optics has replaced the copper wiring and coaxial cabling used by telephone and cable companies. Both use optical fiber rather than copper for new builds due to its higher bandwidth and lower cost.

But for things like carrying electricity something else is needed. Enter carbon nanotubes.

Researchers from Rice University have managed to produce a cable using carbon nanotubes for carrying electricity.

Enrique Barrera, a professor of mechanical engineering and materials science at Rice, said that highly conductive nanotube-based cables could be just as efficient as traditional metals at one-sixth of the weight. He added that such cables may initially find use in applications where weight is a critical consideration, such as in airplanes and automobiles. In the future, he said, it could replace traditional wiring in homes.

The university's release continued, "The cables developed in the study are spun from pristine nanotubes and can be tied together without losing their conductivity. To increase conductivity of the cables, the team doped them with iodine and the cables remained stable. The conductivity-to-weight ratio beats metals, including copper and silver, and is second only to the metal with the highest specific conductivity, sodium."

The mention of doping the carbon nanotubes with iodine reminded me of an article I read years ago about conducting polymers, specifically polyacetylene. When doped with iodine the polymer's conductivity increased dramatically. Such a polymer would have all kinds of uses, particularly where weight was a factor (like in aircraft, as mentioned above). If I recall correctly from the article Plastics That Conduct Electricity (Scientific American, February 1988, no link available), the polymer would be used for carrying control and other signals throughout the aircraft, but not power as its conductivity wasn't quite good enough for that purpose. But nothing came of it, at least in the aircraft industry, as optical fiber has supplanted it due to its light weight and virtually unlimited bandwidth.

But carbon nanotubes can carry the required power and do it with less weight. The raw material used to create the nanotubes is limitless, as carbon is one of the most abundant elements on earth, not far behind hydrogen. Depending upon the structure of the nanotube cable, they could carry more current for a given size. This means smaller gauge wiring to carry the same amount of power.

Is there anything carbon can't do?