Raleigh, North Carolina--Scientists at the University of North Carolina and North Carolina State University recently discovered that they could control a carbon nanotube's ability to conduct electrical current to another material--just by rotating the nanotube. This discovery may prove useful to researchers working in fields like wireless communications or micro-robotics by making it easier for them to design electronic devices and actuating systems at the nanoscale level.
First discovered in 1991, carbon nanotubes are structures so small that thousands could fit on the tip of a pen. Their molecular size and mechanical and electrical properties make them prime candidates for use as components in nanometer-sized electronic and actuating devices that many scientists feel are the wave of the future.
"We found that we can change the electrical resistance between the carbon nanotube and a graphite substrate up to a factor of 50 by simply rotating the nanotube," says Dr. Marco Buongiorno Nardelli, a research associate in physics at North Carolina State. "Being able to do this gives nanoscale-device designers a controllable, continuous means of converting mechanical signals into electrical signals--something they have long sought. Being able to adjust the electrical resistance in this way could one day lead to much faster, more energy-efficient electronic devices."