Finally tonight here, a 6-year-old Florida boy and the gift. For the first time, given something he was born without. And the team that made it happen, proving they are all "America strong." Alex... See More
Finally tonight here, a 6-year-old Florida boy and the gift. For the first time, given something he was born without. And the team that made it happen, proving they are all "America strong." Alex crane was born missing part of his right arm. A smiling little boy, perfectly happy to drive his toy car with one arm. But his parents always knew he night ask at some point if he could have another arm. He is now 6, and tonight, with the help of a team of grad students studying engineering at the university of central Florida, he has his new arm. They documented his first moments. Grab it! Reporter: Picking up a football. Good job, buddy. Reporter: A round of applause from his fans. It's a confidence thing. It's going to give him such a different outlook. He's going to have an idea in his head now that he's not different. Reporter: The engineering students were determined to make this boy happy, and to prove something. That you can build a prosthetic arm and can you do it without costing families tens of thousands of dollars. I hope that people look at these other arms that cost $40,000, they have functionality, if we can do this for $350 in just eight weeks, I'm sure we're going to keep pioneering. I hope people are upset. These arms should not cost $40,000. Reporter: Alex practicing with everything. A toy duck. I got the duck! Reporter: His new arm was made on a 3-d printer, much like this one, running on batteries activated by Alex's own arm muscle. And this afternoon, he showed us what happens when he flexing his arm. Flex your muscle, right? And it opens and closes. Like this. Reporter: Alex's mom telling us every day, a new milestone. Offering a wave to "World news." But nothing quite as moving as that first moment after learning how to control his new arm. Turning to his mom for his first hug with both arms. I lost it. I cried. But now it's more emotional, because seeing all the things he can do and how happy he is, that's a lot. That incredible team and one incredible little boy. Alex, we're waving right back.
This transcript has been automatically generated and may not be 100% accurate.