Iron Man Robert Downey Jr. Gives Boy Real ‘Bionic Arm’ [WATCH]

7 year old Alex Pring is just like any other boy his age. He loves riding his bike, and he loves super heroes! But Alex was born with a partially developed limb. A group of inventors called Limbitless built a state of the art prosthetic arm for Alex. The arm can actually read electrical signals from the brain and transmit them to Alex's arm, allowing him to open and close his prosthetic hand. Each arm is created by a 3-D printer and takes anywhere from 40 to 50 hours to make. But Alex's arm had to be special. So the group at Limbitless decided to make his arm look like Iron Man, and then brought in Tony Stark himself to surprise Alex.