Low-cost ankle exoskeleton boosts leg strength discretely

Weighing in under half a kilogram, the device consists of a friction clutch that sits under the sole of the foot, connected to an assistive spring and a soft shank sleeve that wraps around the calf. According to the Vanderbilt team, the ankle exoskeleton costs less than $100 to manufacture and does not require additional components such as batteries or actuators carried on other parts of the body to power the device. It is described in the journal IEEE Transactions on Neural Systems & Rehabilitation Engineering.

"Our design is lightweight, low profile, quiet, uses no motor or batteries, it is low cost to manufacture, and naturally adapts to different walking speeds to assist the ankle muscles," said senior author Karl Zelik, assistant professor of mechanical engineering at Vanderbilt.

"It could also help reduce fatigue in occupations that involve lots of walking, such as postal and warehouse workers, and soldiers in the field."