Jacob Miller met childhood friend Cesar Montes last summer by chance in a Coeur d’Alene bar. While chatting about family, Montes mentioned his younger brother Alex had lost his arm in a car accident. He asked Miller, a mechanical engineering graduate student, if he could help.
Miller accepted the challenge.
He worked with two other engineering graduates — Jessica Darney and Marshall Townsend — and Cesar to create the arm. Townsend had recently bought a 3D printer. Darney, a biological engineer working to become a prosthetics practitioner, suggested exploring e-NABLE, an open-source software that provides 3D printable designs for prosthetics.
Miller said the team tweaked a design found on e-NABLE to better fit Alex and was ready to print the pieces within a week. After Townsend printed the pieces, they bent the plastic to the correct shape using a method called thermoforming.
“When you 3D print something, the plastic comes through a hot nozzle that melts and can be shaped,” Miller said. “Thermoforming takes advantage of that. You boil water and dunk these parts in there, leave them there for 10-20 seconds. What that does is it softens up the plastic again to the point where you can bend it. Then you just hold it there until it re-cools.”
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Alex traveled to Moscow from McCall at the end of August to pick up the finished prosthetic.
The prosthetic Miller made will serve as a transitional tool to help Alex train his brain to use his arm again. A commercial prosthetic arm would have cost $15,000 — and half of the money would have been required up front. Alex said this would take two to three years of saving.
“This prosthetic is not very heavy duty,” Alex said. “It’s made out of printed plastic, so for heavy duty things like carrying a stack of wood, it’s not ideal, this one that (Miller) made me. What it does help with is the everyday things, like holding something still so it doesn’t move, holding a steering wheel.”
Alex said commercial prosthetics are more expensive because they are customized to each individual and use stronger materials. The light plastic his prosthetic is made from is often used to create prosthetics for children, who grow and often need a new prosthetic every few years. The lighter plastic is inexpensive and adjustable, which is perfect for growing children.
In the future, Alex hopes to have a natural-looking prosthetic arm that matches his skin tone. He said he doesn’t feel different, but sometimes strangers staring can get to him.
Alex said he can do everything he could before he lost his arm, but having the prosthetic helps — especially on long drives. He takes road trips often but holding the steering wheel for several hours with only one hand is dangerous. The prosthetic allows him to rest his hand.
The prosthetic also helps Alex in the kitchen. He works as a cook and the prosthetic allows him to hold potatoes, tomatoes and other ingredients steady while he works with them.
Miller will defend his graduate thesis next semester. He hopes to find work in the northwest to stay close to his family and eventually start an engineering firm.
“3D printing resources are abundant now,” Miller said. “They’re readily accessible, they’re easier than you think and cheap. Just because you have a hang up doesn’t mean all hope is lost and you have to go with the traditional route. There’s always some in-between. Easy to say coming from a mechanical engineer, but this technology has the potential to change a lot of lives.”
Lex Miller can be reached at [email protected]