In I, Robot, the humanoid robot who helps Detective Del Spooner investigate a scientist’s death is Sonny. He is a specially constructed NS-5 robot with an advanced positronic brain and the unusual ability to experience dreams.
Sonny becomes important after Dr. Alfred Lanning dies under suspicious circumstances. Spooner believes the death may involve a robot, despite the widely accepted belief that robots cannot harm humans. Sonny’s behavior challenges the assumptions built into the film’s robotic society.
Sonny is not the same thing as VIKI, the artificial intelligence controlling the central network, or the ordinary NS-5 production models. The character was created for the 2004 film, which was loosely inspired by ideas and stories associated with Isaac Asimov’s 1950 collection I, Robot. Alan Tudyk performed Sonny’s voice and motion-capture work.