Source:
http://www.nytimes.com/2006/03/21/science/21find.html?
pagewanted==print
March 21, 2006
For Robots, Fuel Cells That Double as Muscles
By KENNETH CHANG
Ray H. Baughman, a professor of chemistry at the
University of Texas
at Dallas, has not built an android. He has not built
a brain or an
eye or a robotic equivalent of some other complex body
part.
Instead, he has built something that will also be
crucial for future
androids: artificial muscles.
Today's crude humanoid robots already use gears,
pulleys and pistons
to mimic the actions of muscles. But they are
electrically powered,
requiring that they be plugged in and tethered by an
extension cord
or powered by batteries, which drain quickly.
Dr. Baughman's advance, reported in the current issue
of the journal
Science, is that his new muscle fibers double as fuel
cells. Just
like real muscles, they power themselves instead of
relying on
external electrical power. Chemical energy also
delivers a greater
bang.
"The most advanced battery can only store only about
one-thirtieth
of the energy that is stored chemically in fuels such
as methanol,"
Dr. Baughman said.
He and his colleagues have made two types of
artificial muscles. One
is a nickel-titanium alloy coated with platinum, which
causes the
fuel currently methanol, but hydrogen or alcohol
could work, too
to react with oxygen, producing heat. The metal
shrinks; the muscle
flexes. The artificial muscle can apply 100 times as
much force as
real muscle.
Dr. Baughman said the technology was simple enough
that it could
find commercial applications in as few as three years.
The second artificial muscle, currently less powerful,
is made of a
sheet of nanotubes, tiny but superstrong cylindrical
molecules of
carbon. The reaction of fuel and oxygen releases
electrical charges
that repel each other and cause the nanotube sheet to
expand.
To put such artificial muscles into robots will
require solving
other problems, like how to control the amount of fuel
going to the
muscles. "The analogy of a circulatory system is
really what's
needed," Dr. Baughman said.
But for the future, he said, it is not entirely
far-fetched for an
android to walk into a bar.
>
>
___________________________________________________________
Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail
http://uk.messenger.yahoo.com
_______________________________________________
Biofuel mailing list
Biofuel@sustainablelists.org
http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org
Biofuel at Journey to Forever:
http://journeytoforever.org/biofuel.html
Search the combined Biofuel and Biofuels-biz list archives (50,000 messages):
http://www.mail-archive.com/biofuel@sustainablelists.org/
