There probably some that are. I'm more of a physics gal myself but I did a little bit of work with AI in a practical lab but nothing to the degree that scientists focused on it are.
I'd guess that some think if they find a way to allow them to think for themselves yet set parameters that would keep them from becoming too out of control (which would be antithetical really because that's a fenced in free thinker) we won't have much of a problem in the future. But if it can think, it can learn and find a way around those parameters.
Yet for the 'what ifs' in the equation, AI can be a very handy tool considering the progress that mankind is making, opening new boundaries. It really is a Catch 22.