Artificial muscles made with electroactive polymers simply don't hold up to the rigors of constant shape-changing, but a new class of carbon nanotubes may remedy this says Victor Pushparaj at the Rensselaer Polytechnic Institute in Troy, New York. Initial tests with a two-millimeter block containing millions of vertically-aligned nanotubes endured 500,000 cycles while maintaining its shape, and electrical and mechanical properties. The goal is to build the next generation of actuators for robot arms and prosthetic limbs that will last longer and offer smoother, more life-like motion. See the story at NewScientist