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3-D Printed Prosthetic Hand Fit for a Superhero

Albert Chi and Griffin high fiveAlbert Chi and Griffin high five

Every day, when Quinn Cassidy picks up her son, Griffin, from school, he asks her, “What superhero do you want to be?” The 5-year-old, whose underdeveloped left hand packs a good punch even if it can’t throw a ball, is a superhero expert who knows just the right superpower for any situation.

But Griffin doesn’t know that his parents’ heroic quest to find a prosthetic hand for him has already led them to catch a speeding doctor, hack through the insurance jungle, dive into a sea of technology and battle a scary artificial limb before persuading Albert Chi, a trauma surgeon whose clinical research is focused on advanced prosthetics, to fabricate a custom hand using open-source design and a 3-D printer.

“Little Hand”

Griffin was born with a congenital upper limb difference: His left palm is tiny and his fingers are like pearls, though his arm and wrist are normal. He calls the left his “little hand.” But nothing stops him from exploring his world. “Griffin can do anything he puts his mind to,” says Cassidy. “He’s just going to do it differently.”

Before meeting Chi, Griffin’s parents were advised to get a prosthetic hand. With difficulty, Cassidy found a traveling prosthetist under their insurance plan who fashioned what had been considered state-of-the-art for preschoolers: a beige, body-powered artificial hand attached to a long silicone sleeve that covered most of his arm. A strap crossed behind his back to his right shoulder, and Griffin had to shrug that shoulder to make the artificial thumb grasp an object. The sticker price for prosthetic hands runs from $6,000 to $70,000 before insurance, and the hand would have to be replaced every two years.

But at 4 years old, Griffin found the hand scary and refused to wear it. His parents named the new device his “helper hand,” hoping for a positive spin. “But I didn’t find anything he could do with his hand that he couldn’t do without it,” says Cassidy. After a while, Griffin’s parents realized the prosthetic was having a negative effect. They had spent his entire life encouraging him to do whatever he set his mind to. “This made him feel, for the first time, like he couldn’t do something,” she says.  So they backed off.

A Printed Solution

In the spring of 2014, Griffin’s parents learned about lighter, less expensive prosthetic devices that were being fabricated on 3-D printers. Griffin’s father, Steve Matuszek, had friends involved in 3-D printing who wanted to help. They connected with e-NABLE, an organization of 3-D printer owners who share designs and print out prosthetic hands for kids and adults. The hands cost volunteers under $60 each, but they give them away for free. Quinn Cassidy's father jumped in and called Chi, who had recently begun exploring the promise of 3-D printed prosthetics.

Chi met with the family in early September. He recommended a hand designed to pinch and release like the body-powered hand, except that it used Griffin’s own wrist motion to bend the fingers forward. Just a week later, Chi presented Griffin with a durable 3-D printed, glow-in-the-dark, blue and white $50 custom prosthetic hand. “I love it much better,” Griffin said at once.

“Do you want to call it your superhero hand?” asked his mother. He shook his head. “Not yet.” Apparently, he needed to think about it. But after some tightening and adjustments to make the grasping motion work better, and once he’d thrown a few balls around and high-fived everybody in the room, Griffin was ready with his pronouncement. “It’s my Asteroid hand!” he said, adding, “When I'm a teenager, I’ll get an Iron Man hand.”


Griffin wouldn’t have to wait that long. In this room full of real-life superheroes, Chi knew he had to give a colleague his due. Two weeks later, at the e-NABLE conference hosted by Johns Hopkins Medicine, Chi surprised Griffin with his very own Iron Man hand.

“This is really going to open up doors for him,” says Cassidy.

As seen in the 2016 Biennial Report. Learn more.