The world has just got another reason to love Robert Downey Jr! The Iron Man and Avengers star took some time out to present a little boy with a 3-D printed bionic arm. Seven year old Alex was born with a partially developed right arm, and the artificial limb was manufactured to look exactly like Downey’s superhero character’s red and gold robotic arm.

Downey posted a heart-warming video of their meeting on his Facebook page on Thursday. In it, the actor adopted the charming on-screen persona of Tony Stark / Iron Man and engaged in a Stark-esque conversation with Alex, who was dressed in a bow-tie.

Robert Downey Jr
'Iron Man' actor Robert Downey Jr presented 7 year old Alex with a specially-made bionic arm

“Nice bow-tie, by the way,” Downey says to him in a business-like manner. “How were your travels?” Alex went along knowingly, replying in a similarly matter-of-fact way “Was very good”.

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The actor then opened two cases, one containing Alex’s arm and a larger one for him. Inspecting them, Downey admits “Actually, I think yours might be better than mine. What do you say we both try them on, do a progress report?”

Trying it on, Alex seemed thrilled with his new arm, complete with a flashing light just like Iron Man’s. He then fist-bumped the actor with it, who said “Bang! Nailed it”.

Later, Downey wrote on his Facebook page: “Had the absolute privilege of presenting a brand spanking new 3D-printed bionic Iron Man arm to Alex, the most dapper 7-year-old I've ever met.”

The artificial arm is the result of a collaboration project between Microsoft One Note’s Collective Project and Limbitless Solutions, the latter of these being a start-up from a group of engineering students at the University of Central Florida with aim of making affordable bionic limbs built using 3-D printing.

One Note acknowledged Downey’s role with a message on their Facebook page saying: “coming together like this is what the #CollectiveProject is all about. Robert, it looks like you might have some competition for your next movie.”

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See Downey and Alex's heart-warming encounter here.