The only thing I know about sentience I learned from reading Isaac Asimov's Robot series and Foundation series. (Spoiler alert: the final book in the Foundation series links the two)

I don't see robots gaining sentience in my lifetime. AI -- sure, we'll have robots making decisions within their programming, but they won't know why and they won't care. I kinda chuckle when I watch the news and see a robot being sent in. Robot or radio controlled machine? Does it make decisions on its own or is it being controlled by a human at the other end of a wireless tether? We're a long way from robotic sentience...