Even today, custom-built prosthetics cost an arm and a leg, but there’s no reason why they should. Right now, we can scan someone’s arm or leg, import that scan into a 3D-modeling program ...

It’s where [Coby Unger] met nine-year-old [Aidan Robinson] and helped him design his very own custom prosthetic arm. There’s a lot of problems with prosthetics for children. They’re very ...