In I, Robot, the NS-5 robot who helps Detective Spooner is Sonny.
Sonny is unusual because Dr. Alfred Lanning secretly designed him with a secondary processing system and the ability to dream. Those differences allow Sonny to act in ways that ordinary NS-5 robots cannot, making him central to Spooner’s investigation.
The film is loosely inspired by Isaac Asimov’s robot stories, but its plot and characters are not a direct adaptation of one particular story. It uses Asimov’s Three Laws of Robotics as a major story element while adding a large-scale conspiracy involving the company U.S. Robotics.
Will Smith plays Detective Del Spooner, while Bridget Moynahan plays robotics psychologist Susan Calvin. Sonny’s distinctive translucent design and emotional responses separate him from the mass-produced robots around him.