At first it looks like bits of plastic, scattered across a table and resting in boxes.
When Jorge Zuniga pieces it together, it looks more like a prop from the set of a superhero movie, something Iron Man might slip on or a gadget for Bruce Wayne.
The mechanical hands, though, are for kids.
Every year, about 1,500 infants are born without fully formed arms in the U.S., according to the Centers for Disease Control and Prevention. They're missing palms or fingers or wrists that bend, so as they grow, they can't grip or grab or throw.
Zuniga hopes his work will someday help kids across the country for a fraction of the cost of a typical prosthetic.
The Creighton University professor started building hands last summer after he discovered the instructions online. Now he's collaborating with the original inventors, modifying the design and sharing his updates on the Internet.
Zuniga uses a 3-D printer on campus to build the hand parts. The printer heats the material so it can be manipulated, reshaped and assembled on the platform, layer by layer, until a rubber finger forms.
“There's an unbelievable amount of potential with technology like that,” said Michael Dixon, president of the UNeMed Corporation. The company, which isn't affiliated with Zuniga's project, works with University of Nebraska Medical Center faculty to commercialize their inventions.
At UNMC, one professor is using a 3-D printer to build bones to test new surgical tools. The printers have been used across the U.S. to create other medical devices, too, such as hearing aids, skin grafts and heart valves.
“We're only limited by our imaginations at this point,” Dixon said.
Nine-year-old Shea Stollenwerk, who was born with no fingers, a smaller palm and a partial thumb on her right hand, received one of Zuniga's mechanical hands this month. A professor at the University of Wisconsin-Milwaukee printed one for her using Zuniga's design.
Shea, who lives about 45 minutes from Milwaukee, had never used a prosthetic until now. Her parents decided to not pursue prosthetic options because the devices were primarily cosmetic or required expensive surgical implants to function and, as a child, she would quickly outgrow them.
Zuniga's prosthetic doesn't look like a normal hand with skin and fingernails, but it costs about as much as a pair of shoes to make, and Shea can use it to pick things up with her right hand for the first time.
“It was very cool to see her use it,” said Shea's mom, Ranee Stollenwerk. “As a parent, you want to see your kid's excitement. You want to see their joy. It's pretty special.”
Zuniga spends about six hours each day working on the hand.
When the professor, an expert in how the body functions, saw the original design, he knew the fingers were too short to be useful and discovered during testing that the plastic material was too slick to grip effectively.
He redesigned the fingers and replaced the plastic with more pliable rubber. He tried more than 150 formulas before he found one that worked.
The first prosthetic looked almost Lego-like. The third started to look like a hand stripped to the bone. The fifth and most up-to-date looks more high-tech, though it's built with several household items.
He uses cord from window blinds to control how the fingers bend and grip, a dial often found on snowboard boots to adjust the cord's tension and padding from the occupational therapy department on campus so the hard material doesn't irritate the skin. A Velcro wrap secures the hand to the arm.
His 4-year-old son, Jorgito, tests each version of the hand, curling his hand into a fist to slip on the device.
He tells his father when the material feels rough on his skin, or that the pointer finger doesn't move quite the way it's supposed to, or that it should be blue. At one point, he suggested adding lights and a laser, Zuniga said, laughing.
Kids “don't want something that looks like a hand,” he said, “they want something that looks like Iron Man.”
So the professor bought some material in Creighton blue and an assortment of other colors to personalize each prosthetic. The color serves as an accent to the otherwise black and paper-white hand.
A finished design takes four hours to print and four more hours to build.
Zuniga's isn't on the market yet, though eventually he'd like it to be.
He said the hands he builds costs between $50 and $100.
Zuniga is waiting for approval from a Creighton University research board to send the hands to kids who need them. Their feedback will help Zuniga improve the design.
He can create hands sized for specific children remotely by looking at pictures of their arms. The photos must be taken from several angles, and the arms need to be shown near a dime, which serves as a sizing reference point.
The parts are so easy to build he can throw a few spare fingers into each box. If one falls off or cracks during a game of tag or while a pint-sized Batman fights off an imaginary villain, Mom or Dad would be able to buy a screw from the hardware store and reattach it.
Then the child can go on pretending to be a superhero, with a superhero hand to match.