Researchers at Massachusetts Institute of Technology, Cambridge, have created the first fiber with digital capabilities, able to sense, store, analyze, and infer activity after being sewn into a shirt.
“This work presents the first realization of a fabric with the ability to store and process data digitally, adding a new information content dimension to textiles and allowing fabrics to be programmed literally, using a single process to connect hundreds of digital devices within a long flexible fiber,” says Yoel Fink, professor of material sciences and electrical engineering, a Research Laboratory of Electronics principal investigator, and the senior author on the study.
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. Or, it might someday store the wedding music in the gown worn on the big day.
Fink and his colleagues describe the features of the digital fiber in Nature Communications. 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 0’s and 1’s.
The new fiber was created by placing hundreds of square silicon micro-scale 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. When it is put it into a shirt, it can’t be felt at all. One wouldn’t detect it or even know it was there.
Digital fibers open up more areas of opportunities and solve problems of functional fibers. For instance, they offer a way to control individual elements within a fiber from one point at the fiber’s end.
The new MIT fiber could be thought of as a corridor with elements like rooms that each have their own unique digital room numbers. 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 fiber also takes a few steps forward into artificial intelligence by including, within the fiber memory, a neural network of 1,650 connections. After sewing it around the armpit of a shirt, the researchers used the fiber to collect 270 minutes of surface body temperature data from a person wearing the shirt, and analyze how these data corresponded to different physical activities. Trained on these data, the fiber was able to determine with 96 percent accuracy what activity the person wearing it was engaged in.
Adding an AI component to the fiber further increases its possibilities, the researchers say. Fabrics with digital components can collect a lot of information across the body over time, perfect for machine learning algorithms. This type of fabric could give quantity and quality open-source data for extracting out new body patterns that were previously unknown.
With this analytic power, the fibers someday could sense and alert people in real-time to health changes like a respiratory decline or an irregular heartbeat, or deliver muscle activation or heart rate data to athletes during training.
The fiber is controlled by a small external device, so the next step will be to design a new chip as a microcontroller that can be connected within the fiber itself, forming a fiber computer.
Image – Associate professor Anna Gitelson-Kahn incorporated digital fibers containing memory, temperature sensors, and a trained neural network program for inferring physical activity into a knitted garment sleeve, paving the way to creating the first digital garment. Courtesy of Roni Cnaani.
************************************************************************************************
For more information:
Massachusetts Institute of Technology
https://www.mit.edu/
