The world of prosthetics is undergoing a major transformation—but it isn’t coming from a billion-dollar lab or a major tech corporation. Instead, the breakthrough began in the basement of a Virginia high school. Seventeen-year-old Benjamin Choi has developed a brain-controlled prosthetic arm that is affordable, safe, and remarkably intelligent.
Choi’s path to innovation began unexpectedly. His original research plan—to study aluminum fuels in a laboratory—was canceled during the pandemic. Rather than abandon the project entirely, he improvised. He converted his family’s ping-pong table into a makeshift workshop and began exploring a childhood fascination: brain-controlled artificial limbs.
Years earlier, Choi had watched a documentary about prosthetics that could be controlled directly by the brain. The technology was groundbreaking but came with major drawbacks—it was extremely expensive, required surgery, and often carried significant risks. That inspired a challenge: could he design a brain-controlled prosthetic arm that was both non-invasive and affordable?
Choi’s answer was yes.
Using a $75 3D printer and everyday materials such as fishing line and rubber bands, he built a prototype capable of reading brain signals through electroencephalography (EEG). Instead of invasive implants, the system relies on two small external electrodes. One is placed on the earlobe to establish a baseline measurement, while the other sits on the forehead to capture brainwave signals. These signals are transmitted via Bluetooth to a microchip embedded in the arm, where an artificial intelligence model interprets the user’s intentions and converts them into movement.
The technical effort behind the project is remarkable. Choi wrote more than 23,000 lines of code and created seven new sub-algorithms to make the system work. He also compressed the AI model so it could run directly on the prosthetic arm’s microchip. To train the system, he collected brainwave data from six adult volunteers performing specific hand movements. Over time, the AI learned to recognize each user’s neural patterns, steadily improving its precision.
The results speak for themselves. Choi’s prosthetic achieves a mean accuracy rate of 95 percent—far exceeding the previous benchmark of 73.8 percent for similar non-invasive devices. Built from engineering-grade materials, the arm is both strong and durable, capable of handling loads of up to four tons. Even more impressive is the cost: less than $300, compared with the tens—or even hundreds—of—thousands typically required for commercial prosthetics.
Choi’s innovation has quickly attracted attention. He was named a Top 40 finalist in the Regeneron Science Talent Search and received awards at both the Microsoft Imagine Cup and the Regeneron International Science and Engineering Fair. More importantly to him, the project has begun connecting with the people it aims to help. Joseph Dunn, an upper-limb amputee, reached out with feedback that helped refine the arm’s functionality. Collaborations with researchers at MIT and Stony Brook University have also brought the design closer to potential clinical trials.
Choi’s ambitions extend well beyond prosthetic limbs. He believes his AI-driven brainwave interface could eventually control wheelchairs, assist communication for people living with ALS, and power a wide range of assistive technologies. With two provisional patents already underway, he’s laying the groundwork for a future in which these devices are far more accessible.
What truly sets Choi apart isn’t just technical skill—it’s perspective. Rather than chasing expensive, complex solutions, he focused on making advanced technology affordable and practical for the people who need it most.
His story is a reminder that innovation doesn’t always happen in corporate labs or elite research centers. Sometimes it begins in the most ordinary places—with a ping-pong table, a 3D printer, and the determination of a teenager who believes there must be a better way.
