New research published in Nature Biomedical Engineering highlights a savvy innovation for those struggling with balance: snake skin-inspired shoe grips. Developed by collaborators from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and MIT, the innovation could be used to reduce the risk of falling among older adults.
"Falls are the leading cause of the death for older adults and the second leading cause of occupational-related deaths," said co-corresponding author Giovanni Traverso, who is an assistant professor of Mechanical Engineering at MIT. "If we could control and increase the friction between us and the ground, we could reduce the risk of these types of falls, which not only cost lives but billions of dollars in medical bills every year."
These aren’t just any old friction grips, though. These flexible steel grips were designed to mimic snake scales using the Japanese art of paper cutting known as kirigami. With cuts in the steel sheet, the grip adjusts to your foot’s gait as you walk. Eureka Alert explains: “When the material stretches, the cuts pop out into spikes that dig into the ground and create friction. When the foot flattens, the spikes fold back into the material, creating a smooth surface again.”
"As you walk, the curvature of your shoe changes," said co-lead author Sahab Babaee. "We designed these assistive grippers to pop-out when weight shifts from the heel to the toe and the shoe bends and stretches along the soles."
In developing the technology, the researchers analyzed different gaits on varying surfaces such as ice, which poses a sometimes deadly threat to many balance-reduced folks. In this way, they figured out the best way to maximize the grip with differing surfaces. They hope that their innovation will make life safer for those prone to falling.
"These lightweight, kirigami metasurfaces could play an important role in public health to mitigate slipping and falling in a range of different environments," said co-corresponding author Katia Bertoldi. "They could also be used to improve the mobility of all-terrain robots that could one day travel across difficult environments for search and rescue missions."