Stretchable Liquid-metal fibers stretch 10x to power smart clothing

Researchers at EPFL have developed a novel fiber-based electronic sensor that remains fully functional even when stretched over ten times its original length, marking a significant advancement for wearable electronics. The key innovation lies in using a safe, flexible liquid metal alloy of indium and gallium, combined with a thermal drawing process adapted from optical fiber manufacturing. This technique involves creating a large-scale “preform” with a 3D pattern of liquid metal droplets embedded in a soft elastomer matrix, which, when heated and stretched, produces thin fibers with finely tuned electrical properties. This structure allows selective activation of conductive areas within the fiber, resulting in sensors that maintain high sensitivity and conductivity despite extreme stretching. To demonstrate practical applications, the team integrated these fibers into a soft knee brace capable of accurately monitoring joint movements during various activities such as walking, running, and jumping. The fibers’ combination of stretchability, conductivity, and ease of integration makes them promising for smart textiles used in sports, health monitoring, physical rehabilitation, and