Prosthetics next step

Associate professor of electrical and computer engineering Mircea Teodorescu (right) and graduate students Erik Jung (left) and Victoria Ly are using a design approach called tensegrity to build a low-cost prototype prosthetic that mimics the anatomical motion of a real leg. Credit: C. Lagattuta.

When Erik Jung toured an exoskeleton company in high school, he witnessed how the device helped a paralyzed man, shedding tears of joy, walk for the first time in 20 years. That moment inspired Jung to study how robotics can help people.

Today, he’s a graduate student in the lab of Mircea Teodorescu, associate professor of electrical and computer engineering. With graduate student Victoria Ly, they’re designing prosthetic legs that mimic the anatomical motion of the real thing, using an approach called tensegrity. In place of bones, tendons, and ligaments, the prosthetic has a balanced system of rigid rods and elastic bands, all pulling and pushing on one another, distributing forces like a real leg. Electric motors act as muscles to add extra push as needed.

“It could lead to potentially cheaper prosthetics that feel more natural to users,” said Jung. An unnatural gait, common in amputees using conventional prosthetics, can lead to pain and discomfort. Robotic exoskeletons work, but each device can cost tens of thousands of dollars.

Tensegrity, Teodorescu said, doesn’t need as much electronics, which cuts the cost. The team’s working prototypes, which are still far from what someone would use, only cost about $100. The researchers are still working out basic function and control, he said, but hope to begin human testing soon.

—Marcus Woo