Intelligent algorithms are starting to perceive sights and sounds like human beings. Androids are taking more anthropomorphic forms, powered by actuators wrapped silicone and latex skins. Even these skins are becoming increasingly lifelike. Earlier this year, researchers created an artificial material that's twice as sensitive as human skin. And this month, a team of Oxford professors proposed a provocative idea -- grow human tissue on humanoid robots.

Scientists are already growing muscles, bones, and mini-organs in the lab. But these tissues are generally small, simple, and kinda wimpy. That's partly because a Petri dish is no match for the human body. Take, for example, skeletal muscle. Bioreactors--typically warm, moist vats where cells are grown--might induce some simple movements in lab-grown muscles, but it's nothing like the multidirectional bending and stretching of the human body, which helps our muscles grow and get stronger.