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 Posted: Thu Nov 10, 2005 5:02 pm Post subject: Light could trigger super-fast synthetic muscles |
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Robots using artificial polymer "muscles" are real slowpokes, as the polymers react a hundred times slower than human muscle. But in the future, robots could run circles around humans, with synthetic muscles 1000 times faster than ours.
The possible breakthrough comes from work showing how the polymer muscles work at a fundamental level, and suggests a way of triggering them that could make the muscles less bulky and vastly quicker.
The polymers analysed by the researchers from the Massachusetts Institute of Technology in the US are called conjugated polymers. These conduct electricity and won their discoverers the Nobel prize for chemistry in 2000.
The polymers contract when an electric current is run through them, but to work they have to be bathed in a fluid or gel electrolyte. And while they can be stronger than human muscle, their reaction times are slowed down by the time needed for charge-carrying ions to diffuse through the material.
Speed of light
Sidney Yip’s MIT team started from basic quantum mechanics to explain how the polymers work at a theoretical level. Scientists already knew the contraction of the artificial muscles depended on solitons – a solitary wave that carries a charge along the length of the polymer (see graphic) – but the detailed mechanism was unclear.
The researchers used mathematics to determine how the soliton affected the polymer and discovered that ions do not actually have to be added to the polymer. Instead, light at exactly the right frequency could also activate the wave of charge, and do it much more quickly.
Xi Lin, one of the MIT group, said that to operate artificial muscles exactly as described in the paper might be a decade or more away due to technical challenges. But an understanding of the basic physics might help other experimentalists figure out other ways to build faster muscles sooner, he says.
The artificial muscles could potentially be used in human-like robots or artificial limbs. If so, the new advance might one day result in bionic people with superhuman speed and strength.
Journal reference: Physical Review Letters (vol 95, article 198303)
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Tom Elner, BEAM robotics@ Liverpool Uni
http://www.tombot.net |
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