Researchers at MIT have created the first fiber with digital capabilities, able to sense, store, analyze and infer activity after being sewn into a shirt. The digital fiber contains memory, temperature sensors and a trained neural network program for inferring physical activity, according to a report from the MIT news service.
Yoel Fink, professor of material sciences and electrical engineering, a Research Laboratory of Electronics principal investigator and the senior author on the study, says digital fibers expand the possibilities for fabrics to uncover the context of hidden patterns in the human body that could be used for physical performance monitoring, medical inference and early disease detection.
Until now, electronic fibers have been analog — carrying a continuous electrical signal — rather than digital, where discrete bits of information can be encoded and processed in 0s and 1s, the report says. The new fiber was created by placing hundreds of square silicon microscale digital chips into a preform that was then used to create a polymer fiber. By precisely controlling the polymer flow, the researchers were able to create a fiber with continuous electrical connection between the chips over a length of tens of meters.
The fiber itself is thin and flexible and can be passed through a needle, sewn into fabrics, and washed at least 10 times without breaking down. According to MIT Ph.D. student Gabriel Loke, a lead author on the paper, “When you put it into a shirt, you can’t feel it at all. You wouldn’t know it was there.” Making a digital fiber “opens up different areas of opportunities and actually solves some of the problems of functional fibers,” he says.
The research team devised a digital addressing method that allows them to “switch on” the functionality of one element without turning on all the elements. A digital fiber can also store a lot of information in memory. The researchers were able to write, store and read information on the fiber, including a 767-kilobit full-color short movie file and a 0.48 megabyte music file. The files can be stored for two months without power.
The large team includes several from MIT, as well as Harrisburg University and Rhode Island School of Design (RSID). The research was supported by the U.S. Army Institute of Soldier Nanotechnology, National Science Foundation, the U.S. Army Research Office, the MIT Sea Grant, and the Defense Threat Reduction Agency.