From rdmag:
Researchers at the UT Dallas Alan G. MacDiarmid NanoTech Institute have demonstrated a fundamentally new type of artificial muscle, which can operate at extreme temperatures where no other artificial muscle can be used—from below the temperature of liquid nitrogen (-196°C) to above the melting point of iron (1538°C).
The discovery is reported in the March 20 issue of Science under the title “Giant Stroke, Superelastic Carbon Nanotube Aerogel Muscles.”
Artificial muscles