AIM (Apple, IBM, Motorola) alliance partner IBM has demonstrated a computer circuit made from a carbon nanotube.

A nanotube is a tube-shaped molecule of carbon atoms 100,000 times thinner than a human hair. The scientists created a logic circuit from a single strand of the material. Current microprocessors contain three such logic circuits. These are used to decode binary data.

Scientists at IBM say they discovered a way to allocate two different ways of carrying electrical current on a single nanotube, making it suitable to function as a voltage inverter. All previous carbon nanotube transistors could only carry electrical current in one way, according to IBM.

Carbon nanotubes will replace silicon when current chip features just can't be made any smaller, IBM said. The company expects this to occur in about 10 to 15 years. This technology promises not only smaller, but also more powerful computers as chipmakers will be able to fit more transistors onto a chip.

IBM scientists are working to improve the performance of individual nanotube transistors and to integrate them into more complex circuits.

The circuit was presented Sunday at the National Meeting of the American Chemical Society in Chicago.

This is IBM's second achievement using carbon this year. In April, the same IBM team presented a technique to produce arrays of carbon nanotube transistors.