Lean, Mean Nanomachine

The recent development of nanoscale computing components such as transistors and wires provides tantalizing hints of a future filled with smaller, faster, and more powerful computers. But creating molecular-sized components is only half the battle--in the 9 November 2001 issue of the journal Science, researchers have figured out a way to connect those single devices together to build a lean, mean nanocomputing machine.

Charles M. Lieber with the nanowire building blocks of tomorrow's computers dissolved in solution (prior to organization into devices). Courtesy of C.M. Lieber

Yu Huang and colleagues from Harvard use a bottom-up approach (assembling devices from solution rather than etching them out of solid material) to create diodes and transistors out of crossed semiconductor nanowire junctions and junction arrays. The arrays can be configured as OR, AND, and NOR logic gates, and further interconnected to form computational circuits. "The predictable assembly of logic OR, AND, and NOT (NOR) gates enables the organization of virtually any logic circuit and represents a substantial advance compared with previous studies of nanotubes and molecule systems," say the researchers.

This report, as well as a recent report on nanocircuits and a report on single-molecule transistors published online by Science (18 October 2001 and 8 November 2001; http://www.sciencexpress.org), represents "dramatic steps toward the realization of electronic nanocomputers," says Greg Y. Tseng of Stanford University and James C. Ellenbogen of the MITRE Corporation in a related Perspective article.

--Becky Ham