NASA will pay Rice University $11 million over the next four years to develop an experimental power cable made from carbon nanotubes, the agency announced Tuesday.
The cable, also known as a quantum wire, would theoretically conduct electricity up to 10 times better than traditional copper wire and weigh one-sixth as much.
Scientists believe quantum wires could make spacecraft much lighter and more powerful, and may lead to faster computers and other commercial applications.
Under the agreement with NASA, Rice’s Carbon Nanotechnology Laboratory is to produce a 1-meter-long prototype of quantum wire by 2010. To date, scientists have been able to produce wires no longer than several centimeters.
“This is a small step but a very significant one from our perspective, as we try to develop new technology that will help us as we send humans out from Earth and into space,” said Jefferson Howell Jr., director of NASA’s Johnson Space Center.
The researchers have no easy task before them. To succeed, they will first have to devise a way to produce perfect carbon nanotubes on demand.
Discovered in 1991, carbon nanotubes are tiny, molecular cylinders formed purely of carbon atoms. They are created by shooting high-powered lasers at a carbon target. Each nanotube is just one nanometer in diameter, or 10,000 times smaller than the width of a human hair.
Currently only 2 percent of all nanotubes can be used as quantum wires, and sorting these — called “armchair nanotubes” — from the rest is nearly impossible, according to Richard Smalley, director of the Carbon Nanotechnology Laboratory.
Researchers at the lab believe they can get around this problem by growing the desired nanotubes like crystals. By placing “seed” nanotubes in a laboratory reactor and pumping in carbon monoxide, or some other source of carbon, they hope to create perfect — and long — armchair nanotubes every time. Twisting these together will then produce a quantum wire like the one NASA wants.
“This is not a straightforward applied-research project where we know it’s been done and we need to scale it up,” said Smalley. “We’re going to do major pioneering in this process.”
NASA hopes to outfit future spacecraft with quantum wires rather than heavier copper wires. Doing so could shave critical pounds, which would save money on fuel and, ultimately, allow the craft to go farther into space.
Some engineers have also talked about building a 62,000-mile-long tether made of nanotubes for a space elevator that would carry astronauts and cargo into orbit.
“As we look forward to going to the moon, Mars and beyond, (nanotubes) will certainly, in my view, be a key part of doing that,” said Howell.
Carbon nanotubes may benefit other industries, too. For instance, in 2003, NASA researchers described in the journal Applied Physics Letters how circuit manufacturers might create faster processors by replacing copper interconnects with nanotubes, which are more resistant to heat.
Other researchers have explored using carbon nanotubes to build next-generation flat-panel displays. The displays might feature a tiny nanotube-based electron gun behind each pixel rather than using a single gun for the entire display, like traditional cathode ray tube monitors.
In fact, carbon nanotubes seem so versatile that scientists believe they may one day end up in everything from batteries to military armor — provided that they can be produced easily and cheaply.
“There is a new miracle polymer to be developed,” said Smalley. “I believe this is a tremendously important objective for modern society.”
By Amit Asaravala