If you haven’t seen this video, its pretty damn cool. Robert Downey, Jr. delivered a bionic arm to a young boy who was born without one. The boy, 7-year old Alex Pring, was born missing part of his right arm. The arm was designed by Albert Manero, a PHD in engineering, and a team of students at the University of Central Florida. A prostetic like this costs tens of thousands normally, but by using a 3D printer Manero and his group can make them for hundreds and gives them away to children who need them.