Chips take a dip

Physicists at the University of Pennsylvania have overcome a major hurdle in the race to create nanotube-based electronics. In an article in the August issue of the journal Nature Materials, the researchers describe their method of using nanotubes, which are tiny tubes entirely composed of carbon atoms, to create a functional electronic circuit. Their method creates circuits by dipping semiconductor chips into liquid suspensions of carbon nanotubes, rather than growing the nanotubes directly on the circuit.

"Given their amazing electric properties, nanotubes have been a subject of keen interest for creating such things as chemical sensors, flexible electronics and high-speed, high-device-density microprocessors for computing," said Alan T. Johnson, associate professor in Penn's Department of Physics and Astronomy. "The problem is that the properties we like best about nanotubes their size and physical properties also make them very difficult to manipulate."

Instead of growing nanotubes in a pattern on a silicon chip, as is conventionally done, the Penn researchers devised a means of "sprinkling" nanotubes onto chips.