Too Hot! wrote to mention a BBC article about extremely powerful synthetic muscles. From the article: "The most powerful type, 'shorted fuel cell muscles' convert chemical energy into heat, causing a special shape-memory metal alloy to contract. Turning down the heat allows the muscle to relax. Lab tests showed that these devices had a lifting strength more than 100 times that of normal skeletal muscle. Another kind of muscle being developed by the team converted chemical energy into electrical energy which caused a material made from carbon nanotube electrodes to bend."