Swedish researchers develop textile “muscles”

Researchers at Linköping University and the University of Borås in Sweden have developed electro-active textile muscle systems that turn everyday apparel fabrics into artificial external musculature. The technology may aid people with disabilities, laborers and others who need a boost when lifting and pulling.

Seeker and www.phys.org report how the system works: Lightweight apparel fabric is coated with an electro-active material in a process similar to dyeing. After the material dries, any low voltage current applied to the fabric—such as with a wearable battery—changes the shape of the fabric and produces force in a designated direction or configuration. As the individual threads change volume, the particular pattern or weave in the fabric amplifies and directs movement. The team has coined the term textuator to describe the textile actuator, or the textile “muscle.”

“If we weave the fabric, for example, we can design it to produce a high force,” said Nils-Krister Persson, associate professor in the Smart Textiles Initiative at the Swedish School of Textiles, University of Borås. “In this case, the extension of the fabric is the same as that of the individual threads. But what happens is that the force developed is much higher when the threads are connected in parallel in the weave. This is the same as in our muscles. Alternatively, we can use an extremely stretchable knitted structure in order to increase the effective extension.” Persson was quoted in www.phys.org.

Textuators will need to be anchored to something on the body, just like our muscles are. Edwin Jager, one of the physicists working on the project, explains that the anchor could be similar to the tight elastic sleeves commonly used to give support for injured joints, like knee and elbow pads purchased at pharmacies or sport shops. The team is also testing ways for the textuators to pull against Velcro bands wrapped around a limb. Jager expects that even rigid elements could be integrated in the textile, using lightweight materials in an automated process.

The Swedish technology differs from other soft exoskeletal systems because it is designed for mass-produced fabrics, such as cotton or synthetic materials used to make clothing worldwide.

“It is our dream to create exoskeletons that are similar to items of clothing, such as running tights that you can wear under your normal clothes,” Jager said in press materials announcing the publication of the research. “Such devices could make it easier for older persons and those with impaired mobility to walk.”

The research was published Jan. 25, 2017 in Science Advances.