WASHINGTON Feb 20 What do you get when you take
fishing line or sewing thread, and coil it up in just the right
No, not a tangle of twine to keep your pet cat entertained.
Instead, scientists have turned this into amazingly strong,
and cheap, artificial muscles that could be used in robots,
prosthetic limbs or woven into "smart" fabrics whose pores
expand in warm weather to keep a person cool and contract in
chilly weather to block out the cold.
In the past, artificial muscles have been crafted out of
materials including metal wires and carbon nanotubes, but they
have proven to be costly to make and tricky to control.
According to research published in the journal Science on
Thursday, these scientists instead turned to high-strength
polymer fibers made of polyethylene and nylon, materials found
in everyday items like fishing line and sewing thread. They
twisted the fibers into very tight coils and used changes in
temperature to make the artificial muscles contract and relax.
Scientists from the United States, Canada, Australia, South
Korea, Turkey and China performed the research.
"These polymer muscles can lift 100 times the weight of
natural muscles of the same size," Ray Baughman, director of the
NanoTech Institute at the University of Texas at Dallas, said in
a telephone interview. "They can generate 100 times the
mechanical power of the same weight in natural muscle."
John Madden, an electrical and computer engineering
professor at the University of British Columbia in Canada, added
in a statement: "It also has a higher power output for its
weight than that of an automobile combustion engine."
The most advanced humanoid robots or prosthetic limbs made
today are limited by relatively bulky motors and hydraulic
systems that can inhibit dexterity, the generation of force and
overall work capability, the scientists noted.
Applications for the new artificial muscles could include:
minimally invasive robotic microsurgery; human prosthetics;
devices that open and close windows in response to temperature
changes to keep a building comfortable; and better robots.
"There was a beautiful woman I met in Korea," Baughman said.
"The closer I got to this beautiful woman, she didn't look so
beautiful. The woman was ... a humanoid robot. She didn't have
enough muscles in her face to express natural emotion: smile or
get angry. She looked robotic."
An interesting practical application could be temperature
adjusting clothing. The researchers wove textiles using the
polymer coils that could "breathe" with pores that opened in
response to warmth and closed in cold temperatures.
(Reporting by Will Dunham; Editing by Grant McCool)