A lightweight, low-profile, inexpensive ankle exoskeleton could be widely used among elderly people, those with impaired lower-leg muscle strength, and workers whose jobs require substantial walking or running.

The device is believed to be the first ankle exoskeleton that could be worn under clothes without restricting motion. It does not require additional components such as batteries or actuators carried on the back or waist, enabling it to more seamlessly integrate into daily life.

Researchers invented an unpowered friction clutch mechanism that fits under the foot or shoe and is no thicker than a typical shoe insole. The complete device, which includes a soft shank sleeve and assistive spring, weighs just more than one pound.

The unpowered ankle exoskeleton costs less than $100 to fabricate, without factoring in optimized design for manufacturing and economies of scale. It naturally adapts to different walking speeds to assist the ankle muscles.

Potential applications range from helping aging people to stay active, to assisting recreational walkers, hikers, or runners. It could also help reduce fatigue in occupations that involve a great deal of walking, such as postal and warehouse workers, and soldiers in the field.

For more information, contact Brenda Ellis at This email address is being protected from spambots. You need JavaScript enabled to view it.; 615-343-6314.