The doctors said it would cost the family of a six-year-old boy US$40,000 (S$50,000) to make him a limb.
But graduate students from the University of central Florida have used a 3D printer to make a limb for the kid born without a right arm. The cost: US$350.
Alex Pring, from Groveland, Florida, was given the new prosthetic arm on Friday by a team headed by student Albert Manero, the Mail Online reported.
The students made the limb in their free time and took them seven weeks, saving the family considerable cost, the report said.
After the little boy put on the arm, which senses muscles in his shoulder and opens and closes, he smiled and gave his mother a hug.
It is the first time that the boy had been able to put two arms around her.
"I feel good," Alex told reporters. "I feel everything good, even my robot arm. It's not even heavy."
The team started building the arm after Mr Manero, an aerospace engineering PhD student, read a letter Alex's mother posted online.
On a website for a community devoted to making prosthetic hands, Ms Alyson Pring wrote that because her son had been born without an arm, their insurance company wouldn't cover the costs.
The costs are so steep for childhood prosthetics because of their quick rate of growth and the constant need to replace the limbs.
Mr Manero was driving his car when he heard a story on the radio about a man in South Africa who used a 3D printer to make a new hand.
"I was really inspired," he said. "When I got back, I talked to my colleagues and friends and said, 'We can do this'."
The team - including friends who study electrical, mechanical and civil engineering - got to work on the arm, which is activated by the electromyography muscle energy on Alex's bicep, UCF Today, the university newsletter, reported.
When Alex out-grows the arm, it'll cost just US$20 for a new hand and US$40 to US$50 for a new forearm.
This article was first published on July 30, 2014.
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