Researchers believe artificial muscles plastics that stretch when a high electrical voltage is applied could be a way to mimic nature's efficiency at accomplishing tasks. Using the technology, future robots may be able to "run on Mars like a cheetah, climb a mountain or a cliff like a gecko, or fly like a bird", says Yoseph Bar-Cohen, a physicist at NASA's Jet Propulsion Laboratory in Pasadena, California, US.
This is from a fascinating article in the New Scientist. The whole is really interesting, particularly later where it comments on the various things they could do with these airships.