It is easy to overlook the prominent role of fabrics and textiles in our lives. We wear them, we sleep on them, and we use them to cover windows and floors. Although we've witnessed a steady stream of advances in materials, fabrics haven't changed much over the years.
That is about to change. New types of fabrics are rapidly taking shape. Unlike past smart textiles that were mostly used to track motion or for visual displays, these robotic fabrics sense motion and movements and adapt accordingly. This makes them ideal for use in athletic training, rehabilitation, and prosthetics.
"Soft artificial muscle filaments … can be programmed to generate desired motion, deformation, and force," explains Thanh Nho Do, a senior lecturer in the Graduate School of Biomedical Engineering and Tyree Foundation Institute of Health Engineering (IHealthE) at the University of New South Wales in Australia. "The possibilities in the
"Fiber-like artificial muscles could form the basis of soft robotic exoskeletons," notes Rebecca Kramer-Bottiglio, John J. Lee Associate Professor of Mechanical Engineering and Materials Science at Yale University. The resulting textiles could lead to adaptive clothing, but also new types of household products and even lightweight, stowable, shape-changing machines, she says.
Living in a Material World
Over the last few decades, technology has become increasingly interwoven with fabrics. Synthetic fibers such as Kevlar and Spandex have changed what we wear—and improved comfort. At the same time, smart casual wear, sportswear, shoes, and even smart business suits have appeared.
Robotic textiles and fabrics reshape the concept. "Advanced fibers and fabrics have the potential to create a whole new platform for experiences through wearables," explains Ozgun Kilic Afsar, a design engineer and graduate research assistant in the Massachusetts Institute of Technology's Media Lab. "These new digital fibers can see, hear, and sense their surroundings; communicate; store and convert energy; monitor unconscious and conscious biological processes like breathing, and even form fibers and fabrics that change their shapes."
Afsar is part of a group that has produced reconfigurable OmniFiber technology using fluidic fiber actuators. The material supports artificial muscle-based textiles that can deliver haptic feedback for breathing. This could benefit athletes as they train as well as individuals recovering from surgery, for example.
MIT researchers are also developing fabrics that incorporate fiber supercapacitors, fiber diodes, fiber transducers, fiber ICs, and memory devices to sense, memorize, learn, infer situational context, and respond to the environment or body with which they're interacting. One design, 3DKnITS, relies on a special type of plastic yarn in a floor mat or garment to sense body motion with 99% accuracy.
At the University of New South Wales, Do and a team of researchers have designed fabrics with tiny silicon tubes, approximately the circumference of a piece of yarn, that are braided and woven into a fabric. Hydraulic pressure stimulation causes the fabric to take on various preprogrammed shapes and forms.
Researchers at the university are also experimenting with more futuristic concepts, such as textile sheets that could grow along human skin and create a smart wearable suit that is always a perfect fit. Do says that such a garment, which he likens to an "ironman suit," could incorporate artificial muscles that could aid rescue workers and create shape-shifting bio-mimicking robots.
"These smart textiles have great potential for many applications ranging from basic fashion to compression garments, wearable haptics, wearable assistive devices for rehabilitation and human augmentation, and soft assistive robots," Do explains.
A handful of clothing manufacturers are now venturing into the space. For instance, clothing retailer Wearable X has developed yoga pants that work with a smartphone app to deliver vibrations designed to improve a person's posture. Meanwhile, Siren Diabetic Socks measure foot temperature and sense ulcerations.
Yet key challenges remain. Kramer-Bottiglio says that balancing comfort, washability, and functionality is difficult. Materials coming out of research labs tend to be a bit bulky. "Future work will require more advanced simulations along with design tools that optimize fiber placement, robust thin-body controls, and lightweight embedded power supplies."
Artificial muscle filaments used in these smart textiles must shrink, says Do. His research group is studying ways to reduce .5-millimeter diameter threads to .1 millimeters. Striking the right balance between fashion, mechanics, and durability is critical, but there's also a need to avoid overstimulation for people wearing smart clothing. "Too many signals and too much buzzing will cause people to feel overwhelmed," Afsar adds.
Still, the field continues to advance. Kramer-Bottiglio says smart textiles will introduce changes that extend to all aspects of life. This includes smart curtains that automatically respond to light and temperature, self-deploying tents and shelters, and medical devices that adapt to specific needs of a body.
Concludes Afsar, "For thousands of years, we used fabrics in very much the same way, to provide basic warmth, protection and aesthetics. …The fusion of active materials that respond to fluidic, thermal, or electrical triggers in textile forms will deliver enormous advances."
Samuel Greengard is an author and journalist based in West Linn, OR, USA.
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