January 13, 1999
Web posted at: 3:10 PM EST
(AP) -- Scientists have made a moving part out of a few strands of DNA, a step toward building incredibly tiny "machines" that could someday perform intricate jobs like building computer circuits and clearing clogged blood vessels in the brain.
The hinge-like part, which bends on cue, is just four-ten-thousandths of the width of a human hair.
The new work isn't the first time scientists have turned chemical compounds into moving parts. But previous examples have been hampered by their floppy nature. The DNA device, however, is particularly rigid and executes motions 10 times bigger, lead researcher Nadrian C. Seeman said.
The device was made by joining two double-stranded DNA spirals with a bridge of DNA. When it's exposed to a particular chemical solution, part of the structure bends.
The findings were reported in Thursday's issue of the journal Nature by Seeman and colleagues at New York University. The team hopes to eventually build other moving parts using DNA, including "arms" and "fingers" that someday could be mounted on a micro-robot.
The work is the latest twist in the fledgling field of nanotechnology, or technology at an atomic scale. "This is a very beautiful demonstration of construction at that scale of a device that's actually functioning," said Daniel T. Colbert of Rice University's Center for Nanoscale Science and Technology.
However, Colbert said scientists are still decades away from creating any useful machines in nanotechnology. "We're kind of in the children's playtime toddler era of doing this. We've been thrown some blocks and Legos and Tinker Toys," he said. "We're just kind of picking them up and trying to assemble things out of them that can perform something useful."
K. Eric Drexler of the Institute for Molecular
Manufacturing in Los Altos, Calif., agreed that Seeman's device is too
cumbersome to be useful. But he said further development may lead to a