not your average wearable Single-fiber computer could one day track your health "Soldiers will be the early adopters and beneficiaries of this new technology, integrated with AI systems." Jennifer Ouellette Feb 26, 2025 4:15 pm | 14 US Army Major Hefner training in Norway wearing Fiber computer base layer. Credit: US Army Cold Regions Research & Engineering Lab US Army Major Hefner training in Norway wearing Fiber computer base layer. Credit: US Army Cold Regions Research & Engineering Lab Story textSizeSmallStandardLargeWidth *StandardWideLinksStandardOrange* Subscribers only Learn moreImagine heading out for a run on a cold winter day clad in athletic gear with sensors and microelectronics woven into the very fiber to constantly monitor your vital signs, even running the occasional app. MIT scientists have manufactured a single fiber computer embedded with all the components to do just that, according to a new paper published in the journal Nature.Our bodies broadcast gigabytes of data through the skin every second in the form of heat, sound, biochemicals, electrical potentials, and light, all of which carry information about our activities, emotions, and health," said co-author Yoel Fink, a materials scientist and engineer at MIT. "Unfortunately, most if not all of it gets absorbed and then lost in the clothes we wear. Wouldnt it be great if we could teach clothes to capture, analyze, store, and communicate this important information in the form of valuable health and activity insights?As previously reported, consumers scooped up more than 100 million units of such wearable devices as smartwatches, fitness trackers, augmented reality glasses, and similar tech in the first quarter of 2021 alone. Sales in the category increased 34.4 percent in the second quarter from Q2 2020, making it one of the fastest-growing categories of personal electronics. But while these devices do produce useful data, there are drawbacks. They can be heavy, uncomfortable when worn for long periods, and inaccurate since they usually only measure bodily signals from one spot (e.g., the wrist, chest, or finger).A fiber computer woven into apparel, by contrast, could monitor sensors and collect data from many points distributed across the body, according to the authors. In 2021, Fink's group successfully created the first fiber, sewn into a shirt, with the ability to digitally sense, store, and analyze a person's activity. Until then, electronic fibers had been analog. Hundreds of square silicone microchips were embedded in a polymer preform to create the fiber, and by controlling the polymer flow during manufacture, the team was able to ensure continuous electrical connection among the microchips in a fiber tens of meters long.The resulting fiber was thin, flexible, easily sewn into fabrics, and washable and could incorporate optical diodes, memory units, sensors, and other components. As proof of principle, Fink's team stored a 767-kilobit short movie file and a 0.48 megabyte music file in the fiber, envisioning a day when one could store one's wedding playlist in the bride's gown (or groom's tuxedo).A single-fiber computer Knotted computer fiber. Yoel Fink Knotted computer fiber. Yoel Fink Braiding a computer fiber with a combination of metal and textile yarns. Hamilton Osoy, IFM Braiding a computer fiber with a combination of metal and textile yarns. Hamilton Osoy, IFM Knotted computer fiber. Yoel Fink Braiding a computer fiber with a combination of metal and textile yarns. Hamilton Osoy, IFM But that earlier fiber was limited to fairly simple devices that could be incorporated and was not quite as elastic and flexible as actual fabrics. So Fink and his colleagues decided to rethink their approach. They particularly tackled what they describe as a "geometric mismatch": The fiber is cylindrical but the chips are flat, making it challenging to find sufficient space to connect wires to conductive areas (known as "pads") on more complex micro devices.The solution: Fink's team was able to map the 2D pads to a 3D layout with a flexible circuit board, wrapped into a cylinder. This enabled them to attach four wires to the sides of that cylinder in order to connect all the components: sensors, microcontroller, bluetooth modules, digital memory, battery, and an optical communication system that can send collected data wirelessly to a cell phone. They used a thermoplastic elastomer to make the resulting fiber computer more elastic, capable of stretching as much as 60 percent while still maintaining functionality.Then the fiber computer was covered with braided yarns (polyester, wool, nylon, or silk) and embedded in a pair of leggings. Each fiber had its own machine learning model trained to recognize the exercises being performed with up to 70 percent accuracy. That average accuracy increased to almost 95 percent when the individual fibers were connected into a network to communicate and share data.The fiber computer is currently being tested in the field by a multinational team led by US Army Major Hefner. They are spending 30 days traveling 1,000 kilometers in frigid arctic conditions as part of the Musk Ox II mission. Team members are all wearing base layer computing fabrics to monitor their bodies' response to the extreme cold. It's early days yet, but the long-term objective is incorporating fiber computers into apparel that can sense and respond to changes in the surrounding environment and individual physiology.Future research will focus on creating nano-fabricated custom microdevices with enhanced computational capabilities. "Soldiers will be the early adopters and beneficiaries of this new technology, integrated with AI systems using predictive physiological models and mission-relevant tools to enhance survivability in extreme environments," said Karl Friedl, a scientist with the US Army.Nature, 2025. DOI: 10.1038/s41586-024-08568-6 (About DOIs).Jennifer OuelletteSenior WriterJennifer OuelletteSenior Writer Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban. 14 Comments