Prosthetic Categories

Will Synthetic Muscle-powered Prosthetic Legs Be the Next Thing?

    Artificial muscles are still new, with more laboratory experiments than practical applications. But there’s a promising prototype created by Adaract, a Nevada-based startup working on a synthetic-muscle-powered prosthetic leg.

     The prototype of Atalanta, Adaract's synthetic muscle-powered prosthetic leg, looks promising.

    The device, dubbed the Atalanta, has opened the door to a potentially beneficial frontier in prosthetic research and development. If it delivers on its promises, the device could be stronger, lighter, and more affordable than the available powered prosthetic limbs.

    According to a report on artificial muscles published on MIT’s news website, different approaches have been used to create artificial muscles, such as polymers, shape-memory metals, servo motors, and hydraulic systems. However, all these have limitations, including slow response times and too much weight.

    Hydraulic actuators power Atalanta’s soft muscles, said Joe Hill, Adaract’s lead engineer and founder. The technology is being used commercially in other industries, but it has never been condensed to the scale of a prosthetic leg. “This is a first-of-its-kind application,” Hill said in an interview with Living With Amplitude.  

    Hill explained that the artificial muscles on Atalanta are composed of individual fibers that work together to allocate loads and sustain the effort, like biological muscles. The synthetic muscles can lift more than 80 pounds at total capacity, approximately comparable to the power of a 200-pound adult’s thigh. It is also stronger than any powered prosthesis available today.

    Furthermore, Hill added that the Atalanta prototype works like a human muscle because it recruits additional fibers when the user moves more oversized loads. It also adapts to various situations in real time.

    According to Adaract co-founder Marcus D’Ambrosio, the prosthetic device’s power output will be regulated by the user’s activity. It has a handful of sensors—standard on any microprocessor-controlled knee—that will feed into a machine-learning system to interpret a user’s intent. Simply put, the synthetic muscle’s control system is standard intent-based, which almost all microprocessor knees utilize.

    During Atalanta’s development, Adaract consulted with a handful of amputees and half a dozen prosthetists. Based on their feedback, the company engineered the device to facilitate natural gait biomechanics, increase stamina, and reduce hip and back pain.

    The Atalanta’s synthetic thigh weighs less than a pound than a biological thigh. The prosthetic leg runs on a lightweight battery capable of getting about 8,000 steps in a single charge, and it employs components that Adaract builds in-house to reduce manufacturing costs. As of this publication, the prototype should be in its first field test.

    Fred Moses, an above-knee amputee in line to be Adaract’s first tester, said the technology would be life-changing.

    Presuming things go well, Adaract plans to widen its patient testing later this fall. With encouraging results, the company plans to recruit additional beta testers from the wounded-warrior community and the U.S. Paralympic team.


    If you want to learn more about the synthetic muscle-powered prosthetic leg, visit the company website at