These next gen carbon nanotube muscles have "diamond-like" stiffness side to side, but are as flexible as rubber when moved perpendicularly. When voltage is applied to the structures, they contract with a pulling force 30 times the force per unit of human muscles.
They're also quicker. A human's muscle fibers can contract 10% per second, but these can contract 40,000 percent.
I had no idea synthetic muscles materials have come so far. A few years ago, when I was covering JPL's robotic arm wrestling challenge for Wired, the materials had a fraction of the potential of organic muscles. [Wired]
DISCUSSION
What makes the Terminator scenario appealing is that in term of workability is the easier to implement. In a man-machine meld the human is a weakest link, so, make a better robot and control it remotely. If enough AI can be developed, you'll want it to act independently, to overcome the human limitations, so a form of conciousness is developed...