A new study includes details about a new material that gives users the ability to change the shape, volume, and stiffness of their prosthetic liners in real time with a smartphone. The material, named Roliner, is made from silicone elastomers with channels that can be pressurized to change the material’s properties, meaning its volume and shape can change.
“Just like a basketball, it becomes bigger and more rigid when it is inflated, and smaller and softer when it is deflated,” said Uğur Tanriverdi, PhD, the paper’s first author. Tanriverdi and Firat Guder, PhD, the study’s principal investigator and a member of the faculty in the Department of Bioengineering at Imperial College London, cofounded Unhindr, the wearable robotics company that produces the material. They hope that Roliner will be available for use in the United Kingdom by the end of 2025.
“Prosthetic limbs are often uncomfortable because they have a fixed rigid shape,” said Guder. “Even though this shape can be molded to fit the individual’s body as it is at the time of fitting, it cannot adapt responsively to how our bodies change.
“Up until now, researchers have tried and failed to solve this problem by trying to improve the limbs and sockets themselves. But we took a different approach by developing a dynamically adaptive interface for the liners used between the body and the rigid prosthetic socket.”
Roliner incorporates artificial intelligence so each liner can learn the user’s preferences.
“Currently, most prosthetists still rely on plaster casting and molding techniques that have been used for centuries to determine what socket shape and size will give the most personalized fit. Roliner’s data-driven approach standardizes the quality of prosthetic fittings,” said Guglielmo Senesi, the Imperial engineer building Roliner’s electronics and clinical data architecture, and the chief technology officer at Unhindr.
The researchers believe that the technology could have applications beyond prosthetics, including to increase the flexibility of exoskeletons used in rehabilitation, to modulate the pressure points of hospital beds, or to improve the personalized fit and safety potential of protective gear.
Editor’s note: This story was adapted from materials provided by Imperial College London.
The research, “Dynamically adaptive soft metamaterial for wearable human–machine interfaces,” was published in Nature Communications.
