Researchers created a ring oscillator out of a nanotube. An oscillator switches between two voltage levels, which represent "true" and "false"; they are often used as test vehicles by chip designers. While the oscillator is slower than the equivalent of those made of silicon, the device and subsequent other nanotube circuits will allow IBM and others to more acutely study how nanotubes operate in certain circumstances.
IBM made nanotube transistors before, but an integrated circuit is more complicated. Transistors are essentially on-off switches, while an integrated circuit is a collection of transistors that work together to perform a function. The IBM scientists will now use the ring oscillator to test improved carbon nanotube transistors and circuits, and to gauge their performance in complete chip designs.
"Carbon nanotube transistors have the potential to outperform state-of-the-art silicon devices," T.C. Chen, vice president of Science & Technology at IBM Research, said in a statement. "However, scientists have focused so far on fabricating and optimizing individual carbon nanotube transistors. Now, we can evaluate the potential of carbon nanotube electronics in complete circuits--a critical step toward the integration of the technology with existing chipmaking techniques."
, essentially rolled-up sheets of carbon, have extraordinary properties; they conduct electricity better than metals, are stronger than steel, and can emit light. Many believe that they could one day be used to make everything from smaller, faster computer chips to lighter airplanes.
So far, some manufacturers have sprinkled carbon nanotubes into bike parts and tennis rackets to cut weight and increase the strength of those products. Incorporating nanotubes into chips or devices for delivering medicines into the body could take years.