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.''