I love the idea of using 3D printed muscles for the design of a robot. If you want a robot to function like a human, the best way is to make parts that function like a human. The idea of muscles is a great one that no other robot builders have really ever attempted. The human body is awesome, and it's designed to perfection. So should robots that are designed to act like us. I think 3D printing will be a huge step into designing and prototyping robots.