The 49-year-old Iron Man star recently presented a bionic arm to a 7-year-old fan named Alex, who was born with a partially developed right arm. The arm was built by college student Albert Manero, who builds and donates low-cost, 3D-printed bionic limbs for children around the world.
In the heartwarming video, Downey Jr. remains in character as Tony Stark, referring to himself as a "leading bionics expert." For his part, a snazzily dressed Alex impressively retains his cool demeanor throughout the video, but watch for the cute moment when he acknowledges that he's sitting next to "Iron Man."
"My parents always encouraged me to use my education to help others and to dream big dreams," Albert, who's a doctoral student in mechanical engineering at the University of Central Florida, told Microsoft's blog The Fire Hose last month about his groundbreaking endeavors. "Now I want to inspire others to help engineer hope for the world."
Albert's first arm that he gave to Alex cost less than $350 in materials, which is astounding given the $40,000 price tag of some prosthetics.
"Albert has made it so affordable. I'm probably going to start farming out most of my tech work to Albert too," Downey Jr. jokes in the video. "I feel like he can cut the price point down to one of my suits, which right now is, I don’t know, about a billion and a half dollars."
Downey Jr. is currently busy gearing up for the highly anticipated Avengers 2 premiere, out May 1. ET caught up with the beloved actor and his co-star Chris Hemsworth on the London set, both new dads! Watch below: