Engineers in Germany have built a biologically inspired artificial hand with muscles made from bundles of 'smart' wires. An electric charge is all that's needed to make these wires tense or relax, meaning the hand can operate without the bulky and cumbersome electronics that often make artificial prosthetic hands impractical.
http://in.reuters.com/article/2015/07/22/us-germany-bionic-hand-idINKCN0PW1N820150722