When thinking about what we did during lock down, it’s a wide variety of experiences. Some people created businesses, learned a new skill, or moved from one couch to the other without spilling their overflowing plate of nachos. Then there’s Benjamin Choi, a 17-year-old junior in high school who decided to build a prosthetic arm that could be controlled by brain waves. Choi actually started the extensive project in 2020 at the age of 15 using his sister’s 3D printer. The idea for the prosthetic arm came from a feature on “60 Minutes” about a mind-controlled prosthetic arm, but in order for the arm to work it required surgery to implant sensors on the motor cortex of the user’s brain.
He told Smithsonian Magazine, “I was really, really amazed at the time because this technology was so impressive,” he says. “But I was also alarmed that they require this really risky open brain surgery. And they’re so inaccessible, costing in the hundreds of thousands of dollars.”
The teen’s goal was to make the robotic limb affordable, allowing it to be more accessible. He also wanted to eliminate the need for a surgery that requires digging around in someone’s brain to get the prosthesis to work. Using his sister’s 3D printer for his first prototype was time consuming and required tedious work to connect the pieces since the printer could only print pieces 4.7 inches long. It took Choi 30 hours just to print the parts of the arm before using rubber bands and bolts to put it together. The prosthetic worked using head gestures and brain wave data.
Amazingly, the prosthetic arm isn’t Choi’s first go at coding. Choi has been participating in robotics competitions since elementary school, requiring him to not only build robots, but code them so they move the way he wants. He’s gone to the world championships several times and in 9th grade he taught himself computer programming languages C++ and Python by watching videos on Stack Overflow.
For now, the arm is mounted on a stand. Over the past two years Choi has been working to perfect the arm before adding a socket, which he says would require a recipient to be custom fitted. Currently on its 75th iteration, Choi is still able to maintain the affordability of the prosthetic manufacturing costs being around $300. The current basic body powered upper body prosthesis will run you $7,000.
Choi works with volunteers to collect data and improve the functionality of the AI arm. The high schooler still has a way to go before the arm is complete and ready to be put on the market but that hasn’t stopped him from being recognized. Choi has won awards in Microsoft Imagine Challenge, the Regeneron International Science and Engineering Fair, and the National At-Home STEM Competition. The teen is also a recipient of a manufacturing grant from PolySpectra Inc., awarded in 2020 to help with the production of the arm. PolySpectra produces durable 3D material.
Choi plans to attend college for engineering with a plan to continue working on his prosthetic arm, eventually bringing it to clinical trials. If Choi pulls this off, it could be life changing for the 2 Million people in America that live with the loss of a limb.