Seven-year-old Holden Mora's hand is something that Iron Man might envy. It's bright red, and appears indestructible. Holden was born with something called Symbrachydactyly, and his hand didn't develop properly in the womb.
The 3D hand was created specially for Holden by a UNC biomedical engineering student, Jeffrey Powell. Powell didn't use high-tech prosthetic engineering tools to create the hand. He used a 3D printer.
"It's kind of a new technology to me," says Powell. "I was amazed not only at the fact that you could do it, but how cheap you could potentially do it, with the right printers."
Powell experimented with three existing designs, before settling on the one that worked best for young Holden. The hand allows Holden to grasp water bottles, cups and toys. "It's a great example of a simple but elegant solution to a problem," Powell says.
"You just bend your hand in it and boom, it closes."
Holden says the hand is pretty easy to work, even though his own hand basically ends with the palm. He simply curves his palm as though he were making a fist, and the fingers on his 3D hand close in response. (The 3D hand has tendons that are connected by fishing line which force the fingers to close.)
After the 3D hand was printed and assembled, the two fine-tuned it in Powell's lab on campus. Holden tried out the hand immediately, but soon his skin was irritated by the plastic. Since then, Powell has been working on the hand in the lab, adding padding.
On the day Holden received his new hand back, he was giddy with excitement, bending and unbending the fingers, picking things up and putting them down with the device.
"I just figured out how to move the fingers individually," says Holden, who goes on to give a detailed explanation.
Bargain Basement Price
Though he's only seven years old, Holden is conscious of the high price tags that accompany most prosthetics. In an interview, while Powell is talking, Holden interrupts to say, "I think you should tell them that you don't even need $1,000 to make one of these hands! I think you should tell them you only need $20!"
Powell has relied on other designers in an online community of open source prosthetic builders - People who are sharing designs and tips online. Because of this community, he says, designs for 3D printed hands are improving quickly.
In talking about the ease of printing and the evolving designs, Holden chimes in, "If I got a 3D printer, and a computer that links to it, I could build one of these!"
Jeffrey Powell's friend created this video of Holden and Powell at the lab: