- I am a man of metal-- except for my human brain.
- -- Robotman src
Dr. Robert Crane and his assistant Chuck Grayson worked for years on perfecting a mechanical body that could sustain a human brain after the human body was unable to continue supporting the brain. Criminals found out about Crane's experiment thinking that it could provide a form of immortality and that people would be willing to pay high prices for the highly articulate mobile "iron lung" they tried to steal it and then tried to force Crane to tell them how to operate the robot. Crane refused and attempted to escape. The gangsters shot Crane in order to stop him from turning them in. Seeing their plans ruined the crooks fled leaving Crane to die.
The robot was so heavy that they could not take it with them and without the knowledge to make it work they could not sell it. Seeing that Crane was about to expire completely, Grayson transplanted Crane's brain into the robot body successfully. Robotman let the world believe that Crane was dead and adopted the human alias of Paul Dennis. 
As Robotman Crane continued to operate as independent being, even joining the All-Star Squadron during WWII. However, he was never accepted as an actual person. In fact, lawyer Sam Slattery attempted to have Robotman be declared property of Crane's heirs, but during the trial Robotman revealed his original human identity of Dr. Crane. He also saved the people in the court from the ceiling collapsing. Because of his heroic actions Robotman was legally declared a "living being" but still not as Dr. Crane. Crane accepted the fact that his body had long since died and with it his original identity and accepted the condition of being only "Robotman".
Following the war, Robotman continued to fight crime well into the 1950s (longer than most other WWII-era heroes), often with a talking robot dog named Robbie at his side. His career finally came to an end when he was trapped and buried by a criminal named Lashky. Robotman went into an emergency suspended animation mode, preserving his human brain. He remained buried that way for decades.
When Crane's long time partner and friend Chuck Grayson died, Grayson (believing that Robotman would return some day) had his body frozen to donate it to Crane. Just before the current age of heroes, Robotman was freed and reactivated, and he captured Lashky, now an old man. Then he learned about Grayson's frozen body, and he chose to live for a few years as full human rather than potentially forever inside his mental shell. Robotman's brain was then transplanted into Chuck Grayson's body, possibly by Niles Caulder, and Dr. Crane started his new life as a human being.
- Unique Physiology: Robert Crane is a human brain inside a robotic body, as such possesses all of the various superhuman attributes.
- Although this character was originally introduced during DC's Earth-Two era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and no longer apply.
- Robert Crane was legally declared as dead after being murdered and missing for several years as Grayson removed Crane's brain illegally.
- Robotman was specifically declared a legal citizen of the United States in the late 1940s for his heroic acts but not accepted as Robert Crane.
- In pre-Crisis continuity, Robotman was a native of Earth-Two who migrated to Earth-One (along with Chuck Grayson) for unknown reasons , sometime before his encounter with Lashky. And then he moved back to Earth-Two after his brain was transplanted into Chuck Grayson's body. In New Earth continuity, this dimension-hopping did not happen.
- 198 Appearances of Robert Crane (New Earth)
- 16 Images featuring Robert Crane (New Earth)
- 5 Quotations by or about Robert Crane (New Earth)
- Character Gallery: Robert Crane (New Earth)
- Robotman at dccomics.com
- Robotman (Robert Crane) at Wikipedia.org
- DCU Guide entry on Robotman
- Who's Who: The Definitive Directory of the DC Universe #19