To help individuals who have a hard time getting around or walk all day, Vanderbilt mechanical engineers have created an ankle exoskeleton that can be worn under clothing. The low-cost and lightweight exoskeleton provides support to those with impaired lower-leg muscle strength and workers whose jobs require them to walk or run the majority of the day.
The engineers say this is one of the only exoskeletons that doesn’t restrict motion while being worn under clothing. Additionally, there are no battery packs associated with the device.
“We’ve shown how an unpowered ankle exoskeleton could be redesigned to fit under clothing and inside/under shoes so it more seamlessly integrates into daily life,” Matt Yandell, a mechanical engineering Ph.D. student and lead author of the study, says.
The team was able to eliminate the power element by inventing a friction clutch mechanism that fits under the foot or shoe. The mechanism is no larger than a shoe insole.
In total, the device weighs just over one pound and consists of a soft shank sleeve and assistive spring. It also costs less than $100 to create, which doesn’t include designing the exoskeleton for manufacturing and economies of scale.
“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,” Karl Zelik, assistant professor of mechanical engineering and senior author on the study says.
Zelik says this exoskeleton poses numerous opportunities for individuals in a variety of different fields, such as helping people stay active, providing assistance to the elderly, relieving postal or warehouse workers, and even helping soldiers in the field.
The study was published by IEEE Transactions on Neural Systems & Rehabilitation Engineering.