I don't believe we will use machines in the future. I don't see how it would be possible to come anything close to the processing power, memory skills, data compression, and ability to learn and make judgements as the human brain. Why aren't we machines then if this method is more efficient? For one, I don't see a way for machines to repair themselves unless they had helper bots. They would need to be self-sufficient. They could never survive without us. You would have to design "creator" bots, nursing bots, "cullinary" bots for producing oil/energy, lol, and a whole ecosystem, so to speak. I don't see in a million years AI bots being intelligent enough to take over the human race. I believe what would be more efficient is bio-bots. Produced from cloned humans, which is a scary thought, which couldn't happen for many reasons due to ethical concerns, and a human naturally has free thought and to take that away, you take away all of his judgement skills. I think the future of AI is a dead end road, unfortunately. It kills me to say it since I'm so intrigued by it. Also I forgot to mention the turing problem. But can a being create another just as complex as itself? Well, other than the normal means of reproduction. That's the question, and I don't believe so.