"We may be five to six years ahead of schedule in nanoelectronics, and some of today's research is nearing the stage where it could be turned over to industrial production," said James Ellenbogen of the Mitre Corporation.
A landslide of discoveries brought the promise of powerful electronic and computing devices, built at the molecular scale, to the forefront of scientific research in 2001. In particular, several research teams hooked up tiny devices such as transistors, wires, and switches to form working circuits for the first time.
These devices exist in a realm of miniaturization known as the mesoscale, between one and a 1000 nanometers in size (The diameter of a human hair is 150,000 nanometers, by comparison). Marc Kastner of the Massachusetts Institute of Technology and Charles Marcus of Harvard University discussed recent advances in creating and measuring the activity of mesoscale structures such as quantum dots. These "artificial atoms" could provide the architecture for future nanocomputers.
These computers would contain miniature chips packed with circuitry a hundred thousand times more dense than today's best silicon chips. But before these chips can be assembled, scientists must gain a better understanding of the dynamic behavior of the circuits and their components, said Paul Weiss of Pennsylvania State University and Mark Ratner of Northwestern University. Weiss presented new data on tracking single molecules across a surface, while Ratner discussed how charge transfer takes place on the nanoscale.
"By exploring how one-molecule switches work, we're testing the ultimate limits of logic and memory," Weiss said.
Cees Dekker of the Delft University of Technology shared recent research on the basic electrical properties of individual carbon nanotube molecules. Carbon nanotubes are some of nanoelectronics' most important construction materials, and Dekker confirms that they can be used to create electronic devices and circuits at the single-molecule level.
The first demonstrations of working nanocircuits late last year provided some of the biggest excitement in the field to date. Jan-Hendrik Schön of Bell Labs/Lucent Technologies described his team's success in crafting logic circuits out of self-assembled single-molecule transistors. Schön said that it might be possible to integrate such technology into today's silicon-based circuits, building a bridge between old and new computing power.
"It's been a momentous period for nanoelectronics, with more in store for the future," Ellenbogen concluded.
The researchers' presentations were only one part of the AAAS Annual Meeting nanotechnology seminar, which also covered topics in molecular motors, nano-medicine, and nanophotonics-harnessing light with miniscule devices for telecommunications and other uses.
The American Association for the Advancement of Science (AAAS) is the world's largest general scientific society, and publisher of the journal, Science. Founded in 1848, AAAS serves 134,000 members as well as 273 affiliates, representing 10 million scientists.