From MSNBC:
Robots with oxygen-breathing muscles, aircraft that change the shape of their wings while in the air and other technical advances may be on the way, thanks to a new generation of artificial muscles. Scientists have designed the muscles to run on fuels rather than batteries or electricity from power cords. The new study appears in Friday’s issue of the journal Science, published by AAAS, the nonprofit science society. While the artificial muscles don’t look like bulging biceps or well-defined quads, they are, nonetheless, like natural muscles in important ways: they run on a combination of oxygen and energy-rich fuels and are capable of doing work — such as lifting a metal weight up and down.
More here.