Going for the burn

Researchers at the

have made an important theoretical breakthrough in the understanding of energy dissipation and thermal breakdown in metallic carbon nanotubes. Their discovery will help move nanotube wires from laboratory to marketplace.

The electrical and mechanical properties of metallic carbon nanotubes make them promising candidates for interconnects in future nanoscale electronic devices. However, like tiny metal wires, nanotubes grow hotter as electrical current is increased. At some point, a nanotube will burn apart like an element in a blown fuse.

"Heat dissipation is a fundamental problem of electronic transport at the nanoscale," said Jean-Pierre Leburton, the Gregory Stillman Professor of Electrical and Computer Engineering at Illinois. "To fully utilise nanotubes as interconnects, we must characterise them and understand their behaviour and operating limits."

Up to now, no coherent interpretation had been proposed that reconciled heat dissipation and electronic transport, and described thermal effects in metallic carbon nanotubes under electronic stress, said Leburton, who is also a researcher at the Beckman Institute for Advanced Science and Technology, at the Micro and Nanotechnology Laboratory and at the Frederick Seitz Materials Research Laboratory. "Our theoretical results not only reproduce experimental data for electronic transport, they also explain the odd behaviour of thermal breakdown in these nanotubes."