Wearables and the variety of form factor those can take may soon get a huge boost thanks to a group of researchers from North Carolina State University and their study into soft, stretchable sensors. The team behind the findings – which includes Christopher B. Cooper, Kuralamudhan Arutselvan, Ying Liu, Daniel Armstrong, Yiliang Lin, Mohammad Rashed Khan, Jan Genzer, and Michael D. Dickey – published their findings in the Advanced Functional Materials journal on March 23.
To create their sensors, the researchers used liquid metals filling hollow fibers that are just over the width of a human hair, which were spun together in sets, with each set containing a different amount of liquid metal. The advantage to liquid metals is that, like the "elastomeric" tubes that make up the rigid structure of the fibers themselves, liquid metals can deform while still maintaining "electrical continuity." By filling each fiber with a different level amount of liquid metals and twisting them together into a helix, the team was able to effectively fabricate capacitive sensors that responded to touch, stretching, and twisting in a predictable way. In layman's terms, that means that the fibers can respond to touches in a way that is very similar to how the touch screen on a phone or tablet does. One of the researchers, Michael Dickey, also uploaded a video showing the results of the team's research to YouTube. In the video, the basics of the process for creating the sensory fibers is shown, as well as a basic demonstration using LED lights to show off the fibers ability to sense where a touch was occurring along a fiber.
Because the fibers are completely enclosed in a pliable material, with the copper ends presumably also able to be protected, the fibers could be used in a number of really interesting ways. Moreover, the team says that the process for creating them is simple enough that they could be easily mass produced for use in "textiles" or to "comply with complex surfaces." That leaves the door wide open for use in an array of wearables that are not at all limited to the categories of wearable clothing, watches, or rings. With full capacitive functionality, it also may be possible for those wearables to incorporate the touch-sensitive fibers in ways that go beyond the fitness tracking capabilities currently being explored.