Building machines that process information the same way a brain does has been a dream for over 50 years. Artificial intelligence, fuzzy logic, and neural networks have all experienced some degrees of success, but machines still cannot recognize pictures or understand language as well as humans can.
I think you are abusing the term “sentient”. How about taking a stab at a definition. I read a paper once (I can’t find it now) that said we can create a self-conscious machine easily, just give it a symbol that represents itself, and allow it to reason using that symbols. Done.
We can’t even agree whether other animals are sentient.
We don’t even agree on what “intelligence” means, which should be a much easier term to figure out.