I came across some pretty unusual materials in my occupation. There is a material called nitinol that acts like a servo, reacts to PWM, but is thinner that a hair. It can be used as a muscle and a tendon to give lifelike movement. Also since the strands are small you can place 4 together and get self posing hairs. My old physics professor invented it to make self repairing satelite antennae years ago. Now it is sold over the internet. http://www.robotbooks.com/Muscle_Wires.htm