This Father 3D Printed A Bionic Arm For His Infant Son, And Now Other Kids Can Have One

When Ben Ryan found out his newborn son couldn’t get a functional prosthetic until he was three, he started Ambionics to build them.

When Ben Ryan’s son Sol was born, an injury during delivery led to a blood clot in his arm–and at the age of 10 days, the arm had to be amputated. After Sol left the hospital, the new parents learned that he couldn’t get a prosthetic until he was a year old, and he probably couldn’t get one that would let him grab or hold anything until he was three.


Ryan decided to find a better solution, realizing that if infants could use a prosthetic at an earlier age, they might be more likely to keep using it as a toddler.

“If you don’t get function before the age of two, there’s a high risk that kids will just reject prosthetics altogether,” he says. “There’s a really rapid period of brain growth that ends at about the age of two and a half . . . if you haven’t mastered prosthetic use by the age of two and a half, I believe that’s why rejection occurs.”

Existing prosthetics that can move don’t work well for babies. Arms that use sensors have strong batteries and motors that pose a risk of injury, and the sensors, which have to detect a nerve signal, often can’t work through baby fat. Another type of prosthetic, a body-powered hook, is cumbersome and unnatural-looking.

At his kitchen table, Ryan–who is not an engineer, but likes building things–began mocking up a design for a device that would be light, attractive, customizable, and possible to introduce at a very young age, without parts that could cause a choking hazard.

Inspired by the way spiders’ legs move through hydraulics, Ryan created a design for an arm filled with fluid that could open and close a gripping mechanism as the arm moves. At an innovation lab at a university near his home in the U.K., he 3D printed an early prototype. After watching videos online, he taught himself how to use Autodesk’s free Fusion 360 software, and he refined the design.


The result is a prosthetic that can eventually be custom-designed for children and 3D printed within three days, versus the 10 weeks that it can take to get a custom prosthetic in the British health system currently. It will also be much cheaper. Ryan has now left his job to launch a startup called Ambionics to make the device available to more children. In a crowdfunding campaign, he’s raising funds to get FDA approval and finish the patent and prototyping process.

“Based on how quickly things are developing in Ambionics, it’s clear that Sol and I are going to leave a wake of technology behind us as he grows and shows me what he needs,” says Ryan. “Others should absolutely benefit from that. I intend to completely disrupt the market and bring affordable and effective prosthetic solutions to as many infants with upper-limb differences as possible.”

[Photos: via Ambionics]


About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.