Researchers use nanotubes to create copper-cable replacement

Researchers from Rice University have published results of their efforts to produce cables made of carbon nanotubes that can conduct electricity. The research's ultimate aim is to develop nanocables that can replace copper cables for conductivity.

In a media release, the university explained, "A Rice lab made such a cable from double-walled carbon nanotubes and powered a fluorescent light bulb at standard line voltage - a true test of the novel material's ability to stake a claim in energy systems of the future."

An abstract of the research has been published on Nature.com.

Enrique Barrera, a professor of mechanical engineering and mateials 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."

Yao Zhao, one of the nanocables' developers, recently defended his dissertation toward his doctorate at the university and his the lead author of the new paper. He built the demonstration rig that allowed him to toggle through the nanocable and replace the conventional copper wire in the circuit.

This initial study used a few centimeters of cable; in that regard Barrera remarked that spinning billions of nanotubes into a cable at all is quite a feat. "The chemical processes used to grow and then align nanotubes will ultimately be part of a larger process that begins with raw materials and ends with a steady stream of nanocables," he said. The project's planned next stage will be to make longer, thicker cables taht carry higher current and still keep the cable lightweight. "We really want to go better than what copper or other metals can offer overall," Barrera said.

Tsinghua University partnered with Rice on the research and supplied the nanotubes for it.

Rice researchers Barrera and Zhao discuss their efforts in the video below.