Sentient Beings

What defines a sentient being? What makes something or someone real or unreal?

Popular films such as The Matrix and I, Robot explore these topics. However, just watching the film only skims the surface. One has to dip into the film and explore these topics more in depth.

The definition of sentient is

–adjective
1.
having the power of perception by the senses; conscious.
2.
characterized by sensation and consciousness.

Both of these definitions can apply to The Matrix and I, Robot. For example all the humans that are unknowingly following the matrix are conscious and perceive sensations. Just as the proitronic robots in I, Robot are conscious and can follow their own wills.

Knowing this, does that classify the humans within the matrix and the proitronic robots as sentient beings? If so, do we have to redefine the definition of sentient to make the adjective only apply to us, humans, or when the times comes will we have to broaden the term and open our minds to the possibility that a machine we created can become a living, "breathing", sentient being?