Student Builds Prosthetic With 3D Printer ANNA WARNER: Ask first grader Holden Mora how his new hand works, and he'll be happy to demonstrate. HOLDEN MORA: So when I bend my hand in like this, it closes. When I did this, it opens. ANNA WARNER: At seven years old, he's become an expert on the workings of this novel device, made out of plastic for roughly $20. HOLDEN MORA: It's an amazing $20. ANNA WARNER: It's an amazing $20. HOLDEN MORA: And normally, the materials cost a lot, about like $1,000. ANNA WARNER: He's right. Children like Holden, born without hands or fingers-- in his case, the fingers on his left hand-- often require custom prosthetic replacements costing thousands of dollars. But this inexpensive device was created by a college student using a 3D printer. JEFF POWELL: Builds it layer by layer. ANNA WARNER: Senior Jeff Powell studies biomedical engineering at the University of North Carolina at Chapel Hill. He took on the project after learning about Holden from one of his professors. JEFF POWELL: Hey, try that now. ANNA WARNER: He used instructions posted on the internet called The Cyborg Beast, then customized it. The 3D printer builds the parts in under 24 hours. ANNA WARNER: And at the end, you wind up with is this. JEFF POWELL: Yes. ANNA WARNER: Right? JEFF POWELL: Yes. So the way this works is it straps on to Holden's hand and on to the end of his forearm. When he moves his wrist in, the fingers close. When he moves his wrist out, the fingers open. ANNA WARNER: And do that again. Do they grip strength? So they actually do have grip strength. JEFF POWELL: Yes. ANNA WARNER: His goal, for Holden to be able to do things the rest of us take for granted. JEFF POWELL: To be able to eat dinner while holding a knife and a fork at the same time. Be able to grab onto his scooter, his bike with two hands. Maybe even swing a baseball bat, if we get it that strong enough. I don't want him to be limited by the condition that he was born with. ANNA WARNER: So this isn't just about a hand for him, is it? JEFF POWELL: No. No, it's about enabling him to do anything that he wants to do. ANNA WARNER: Holden's parents believe the impact could be even more profound. PETER MORA: He's less likely to be underestimated when he has a device like that. You know, people won't look at him and be like, oh, well, you can't do that. BRIDGET MORA: There are times when he doesn't necessarily like for kids to ask him about his hand. And because the 3D printed hand is so cool, I think that gives him just a confidence in talking about his hand, which I love. ANNA WARNER: And the payoff for this amateur designer. ANNA WARNER: When he picked up a cup, you were able to say to yourself, hey, this worked. JEFF POWELL: Yes Yes. ANNA WARNER: That had to be a great moment. JEFF POWELL: Yes. It was nice to see it all pay off. ANNA WARNER: Powell has now started a crowdfunding campaign to raise money so other kids can get the device too. HOLDEN MORA: Well, I'm actually really happy, because I think it's true that once I get the best hand, they'll make more like it for those kids, and then they'll have the best kind of hand too. ANNA WARNER: Pretty good grip. ANNA WARNER: Eleven more children are already waiting for their new hands. For "CBS This Morning," Anna Warner, Chapel Hill, North Carolina. HOLDEN MORA: This side actually makes it farther.