X-Message-Number: 11291
Date: Fri, 19 Feb 1999 17:21:17 -0500
From: Jan Coetzee <>
Subject: Artificial Muscles

Tiny Space Rover Will Use Artificial Muscles

By Deborah Zabarenko

WASHINGTON (Reuters) - Artificial muscles destined to be used as
windshield wipers aboard
a tiny space rover might one day be used to make ``bionic''
battery-powered limbs, a U.S. space
scientist said Thursday.

The plastic muscles are designed to give finger-like flexibility to the
palm-sized Japanese Mu
Space Engineering Spacecraft, which will blast off for an asteroid in
2002 and come back to
Earth with samples.

At this point, the artificial muscles aboard Mu will be used to swish
over a viewing window to
keep it clear of asteroid dust.

But Yoseph Bar-Cohen, who heads a team working with the plastics at
NASA's Jet Propulsion
Laboratory in California, said a ``hand'' could be developed using
ribbons of the material.

Such a hand, comprised of four strips of this bendable plastic, is able
to grasp and lift a rock
when an electric charge is run through it, Bar-Cohen said in a telephone
interview from
Pasadena, California.

``It does look like a hand with four fingers,'' Bar-Cohen said,
referring to a laboratory model of
a claw-like object. ''It opens its fingers and closes them, it has
'nails' that are hooks.''

There are two types of artificial muscles under development out of
lightweight polymers: one
type that bends like a finger when activated by electricity, and another
that lengthens or contracts
when activated, Bar-Cohen said.

Such lightweight, flexible materials could change the way space
scientists make robots, which
have been too heavy and too power-hungry for future space missions.

``There is so much incredible potential, because of the (artificial
muscles') similarity to what we
do with our body,'' Bar-Cohen said. ``...It has this resilience that we
have in human muscle and
has a similarity in how it works. It is a simple signal that we give to
make it longer or shorter,
compared to the complex signals we give to move a robot.''

Far in the future, artificial muscles powered by lightweight batteries
could be used to create
``bionic'' limbs for the handicapped, the National Aeronautics and Space
Administration said in
a statement.

Bar-Cohen had a vision of an arm-wrestling match between a person with
an
artificially-muscled arm and a normal person, but said such a contest is
far off.

``Bionic'' human limbs are likely to be preceded by much smaller-scale
robots, possibly robotic
insects designed to work together like ants or even a robotic butterfly.

Such notions may be discussed next month in an engineers' symposium on
artificial muscles in
Newport Beach, California, NASA said.

An Internet site -- http://ndeaa.jpl.nasa.gov -- gives more information
on artificial muscles and
Bar-Cohen's research.



J.C.

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