"Sentience" comes from the same base word as "sensate", which means to have physical senses. The mind, being tabula rasa at birth, requires sensate experience to fill that tabula rasa. This is called "acquired" knowledge.
From this sensate acquired knowledge the mind abstracts what is metaphysically important in the experience.
A computer will never have the ability to abstract what is metaphysically important, as in "what the person using a search engine is looking for." Obviously that knowledge wouldn't come from sensate knowledge. But all things known by man that are not DIRECTLY from sensate knowledge are called "concepts" and are created by the integration of two or more percepts.
How is a computer to have a percept, let alone integrate it with other percepts into the concept of "what a person is looking for"? When I asked Cleverbot "Can Cleverbot ever have sensate knowledge?", it answered with this: "I don't know. You're the cleverbot."
When I asked it "Why am I the cleverbot?" it answered: "Gaww... *blushes* thank you."
I think you mean "sapience", not "sentience", but where is AI to get the epistemic principles that would allow it to have sapience?