The 3D printing technology is perhaps one of the most useful and life-changing technologies of the 21st century. Stories abound on how the technology has turn around lives.

This year alone, doctors in the U.K were able to reconstruct the face of a man who fell from a fifth floor balcony with the help of a 3d printer. Surgeons in Kentucky were also able to reduce the number of unnecessary incisions when they conducted a heart surgery on a 14-month old baby. The story of 6-year old Alex Pring has now been added to the growing list of those whose lives were changed by 3D printing technology.

Alex was born missing an arm which makes it difficult for him to do things other children could do such as fully embrace his mother and for children like him, having prosthetic limbs do not come easy. For one, artificial arms are not cheap. They can fetch up to $40,000 and this is made worse by the fact that because children are still growing, they easily outgrow their prostheses.

Thanks to 3D printing and the ingenuity of Albert Manero, who is pursuing a doctoral degree in aerospace engineering at the University of Central Florida, and his team, though, Alex now has a bionic arm. What makes Alex's artificial arm different is it was made using a 3D printer. It could also sense movement in his biceps allowing him to grip and pick up objects. The 3D-printed arm also works with arms that do not have a working elbow and to top it all, it literally does not cost an arm and a leg.

Building the prosthesis only costs about $350, which is way too cheap when compared with the price of other prostheses on the market and because new parts can be printed for as low as $20 for a new hand and between $40 to $50 for a new forearm, Alex's family won't have to struggle with the cost once he outgrows his current artificial arm.

Alex's mother, Alyson, found Manero through the online network e-NABLE, which is made up of volunteer 3d enthusiasts. One of the group's goals is to help kids without hands. Having a childhood friend who have fingers missing, promoted Manero to join the group.

"My mother taught us that we're supposed to help change the world," Manero said. "We're supposed to help make it better. That's why we did it. The look on Alex's face when he used it for the first time was priceless."