This high school student built a prosthetic arm he controls with his mind

A low-cost prosthetic limb operated by the mind has been designed by an American teenager.

Benjamin Choi, 17, saw an episode of 60 Minutes where researchers implanted small sensors into the patient’s brain, allowing her to control a robotic arm with her thoughts alone.

The operation’s invasiveness, though, led Choi to assume that there might be a better option.

“I was really, truly impressed at the moment because this technology was so astounding,” he told Smithsonian Magazine.

“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.”

Basic body-powered prosthetic arms cost around AU$10,000 (US$7,000), whereas a more modern full-arm Modular Prosthetic Limb costs AU$710,000 (US$500,000).

Throughout his education, Choi had built robots and coded, and he taught himself computer programming languages like Python and C++.

When the pandemic occurred in 2020, he decided to spend his time trying to construct a less-invasive prosthetic arm after seeing the 60 Minutes report.

He printed the arm in tiny parts with his sister’s AU$100 (US$75) printer and some fishing line. Each item was then fastened and rubber banded together.

The high schooler went through 75 versions of his concept until it was finally composed of engineering-grade materials and capable of withstanding up to four tonnes of force.

It controls the arm with an artificial intelligence (A.I.) system that interprets the user’s brain waves.

Electroencephalography (EEG) monitors the electrical activity of the brain using sensors on the head.

Epilepsy and brain diseases are frequently diagnosed with EEG.