I'm not sure of the relationship between World's fair (Expo) and I, Robot (the movie) in the following.
... but his real passion is for building robots. Not industrial car-building machines, or small, cute Roombas, mind you, but real World's Fair, I, Robot, help-you-around-the-house type robots.
Is it saying "he wants to make the kind of robots that appeared in World's fair or the movie I, Robot"?
Yes. Not the kind of robot that is just an arm connected to a computer. The kind that looks more or less human- or animal-like, that can move by itself and perform various tasks.