Using a novel fabrication process, researchers from the Massachusetts Institute of Technology (MIT) have produced smart textiles that snugly conform to the body so they can sense the wearer's posture and motions. By incorporating a special type of plastic yarn and using heat to slightly melt it – a process called thermoforming – the researchers were able to greatly improve the precision of pressure sensors woven into multilayered knit textiles, which they call 3DKnITS.
They used this process to create a "smart" shoe and mat, and then built a hardware and software system to measure and interpret data from the pressure sensors in real time. The machine-learning system predicted motions and yoga poses performed by an individual standing on the smart textile mat with about 99 percent accuracy. Their fabrication process, which takes advantage of digital knitting technology, enables rapid prototyping and can be easily scaled up for large-scale manufacturing, says Irmandy Wicaksono, a research assistant in the MIT Media Lab and lead author of a paper presenting 3DKnITS.
The technique could have many applications, especially in health care and rehabilitation. For example, it could be used to produce smart shoes that track the gait of someone who is learning to walk again after an injury, or socks that monitor pressure on a diabetic patient's foot to prevent the formation of ulcers. "With digital knitting, you have this freedom to design your own patterns and also integrate sensors within the structure itself, so it becomes seamless and comfortable, and you can develop it based on the shape of your body," Wicaksono says.
He wrote the paper with MIT undergraduate students Peter G. Hwang, Samir Droubi, and Allison N. Serio through the Undergraduate Research Opportunities Program; Franny Xi Wu, a recent graduate of the Wellesley College; Wei Yan, assistant professor at the Nanyang Technological University; and senior author Joseph A. Paradiso, the Alexander W. Dreyfoos Professor and director of the Responsive Environments group within the Media Lab. The research will be presented at the IEEE Engineering in Medicine and Biology Society Conference. "Some of the early pioneering work on smart fabrics happened at the Media Lab in the late '90s. The materials, embeddable electronics, and fabrication machines have advanced enormously since then," Paradiso says. "It's a great time to see our research returning to this area, for example through projects like Irmandy's — they point at an exciting future where sensing and functions diffuse more fluidly into materials and open up enormous possibilities."