Uhh... Theoretically artificial intelligence might be possible someday, but that day is pretty far off. Even the "smartest" machines we have, like say, Deep Blue, aren't even as close to sentient as my cat. The real problem with artificial intelligence is machines can be programmed with lots of complex subroutines and commands, calculate large data sets, perform physical tasks, oftentimes better than a person,..but it doesn't understand why it's doing it. It lacks even the most basic intuition or comprehension. It may not be possible to create artificial intelligence ever, but I wouldn't necessarily rule it out.
Well, my point wasn't so much that it's possible now as it was that it's theoretically possible in a purely materialistic worldview. If we are all just synaptic reactions in a biological environment, then that's what we basically are: EXTREMELY complex computers. There is no "spirit" or other outside force/influence that makes our consciousness, sentience, or otherwise-named self-awareness unique or true; it's basically an illusion. If that is in fact the case, then I believe it must follow that a like entity could, even if only theoretically, be constructed from basically non-living matter (much in the way that the simplest life was made from non-living matter, like sugars and minerals) in such a super-complicated way as to resemble human behavior.
For example, it's then theoretically possible to create a "robot" with synaptic responses complex enough to mimic human behavior, feeling and decision. There is nothing in hard materialism that places emotions or perception above the biological functions of our bodies. Which means they are controlled by variables in our brains --- which are theoretically reproducible.
And the point of making that point was that, going on a purely materialistic worldview, there is no way to differentiate between such a theoretical "super-complex machine" and a living human, because they share the same biological synaptic processes.
I guess I should ask before I go on: Do you believe that there is anything about human behavior (from a biological standpoint) that absolutely cannot ever be manually reproduced by any means?
For all the things that I never did
For all the places I never was
For all the people I never stopped
But there was nothing I could do..."