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Conveyor Belt For The Nano-Age - SpaceDaily Left:
A glimpse into
the factory of the future. Four images, each taken 60 seconds apart,
portray the rightward march of indium atoms along a carbon nantoube
subjected to about two volts (courtesy of Zettl Research Group). In
a development that brings the promise of mass production to nanoscale
devices, Lawrence Berkeley National Laboratory scientists have
transformed carbon nanotubes into conveyor belts capable of ferrying
atom-sized particles to microscopic worksites. "We're
not transporting atoms one at a time anymore — it's more like a
hose," says Chris Regan of Berkeley Lab's Materials Sciences
Division, who co-authored the article along with fellow Materials
Sciences researchers Shaul Aloni, Ulrich Dahmen, Robert Ritchie, and
Alex Zettl. Aloni, Regan, and Zettl are also scientists in the
University of California at Berkeley's Department of Physics, where much
of the work was conducted. The ability to shuttle a stream of particles
to precise locations fills a void that has stymied the efficient
assembly of nanostructures. For years, scientists have been able to
simultaneously deliver millions of atoms to millions of sites simply by
mixing chemicals. "It's either all at once, or excruciatingly
serial," says Regan. "So we combined incredibly precise
localization with something that has higher throughput." This
middle ground is made possible by carbon nanotubes, which are hollow
cylinders of pure carbon about ten thousand times smaller than the
diameter of a human hair. Since their discovery in the sooty residue of
vaporized carbon rods, these incredibly strong and versatile
macromolecules have been engineered into frictionless bearings,
telescoping rods, and the world's smallest room-temperature diodes. Now,
they're poised to change the way these and other devices are
constructed. |