Tiny Machine Uses DNA to Do Its
Work Source: Reuters
April 14, 2000
WASHINGTON (Reuters) - A tiny machine that can
physically bend DNA to do its work may be just the first member of a
whole generation of microscopic robots, Swiss researchers said on
Friday.
They might be used to diagnose medical conditions, read
genes or operate microscopic valves for precise drug delivery, the
team at IBM Research in Zurich and the University of Basel in
Switzerland said.
Writing in the journal Science, they said they found
that DNA can be used to bend tiny silicon ``fingers'' that have a
thickness of less than one fiftieth of a human hair.
They rigged up a system of these little cantilevers --
anchored at one end and free to bend up and down at the other -- and
glued single strands of DNA onto the top.
DNA naturally forms a double helix like a twisted
ladder, and when cut apart will naturally try to put itself back
together again.
When the researchers put their cantilevers into a
solution with the missing halves of the DNA strands, the pairs zipped
themselves together and the little cantilevers bent under the force.
The movement could be used to see genetic variations in
the DNA, such as a mutation, but could also itself be harnessed to do
work, the researchers said.
``This biomechanical technique has the potential to
enable fast and cheap biochemical analysis, and could be used for
mobile applications,'' Christoph Gerber of IBM Research, who led the
study, said in a statement.
He said the same technology could look for active
proteins being produced by cells, including those the body produces
during disease or after an injury such as a heart attack.
James Gimzewski of IBM Research said the experiment
showed that the unique properties of DNA could be put to work in tiny
robots.
``We have found a way to get DNA to do the work for us,
so we don't need batteries, motors, or the like to operate tiny
machines,'' he said.
Such a little device might be used to open a valve,
perhaps to deliver drugs in precise doses right where they are needed
in the body.
``For instance, we can envision a system to attack
cancerous growth -- the release of just the proper doses of chemicals
in the appropriate location of the body could be achieved using tiny
microcapsules equipped with nano-valves,'' Gimzewski said.
``They could be programmed chemically to open only when
they get biochemical signals from a targeted tumor type. This would
enable the right therapy at the right place at the right time, with
minimized side effects and no invasive surgery.''