A liquid metal core-shell fiber for stretchable smart fabrics

Flexible sensors have attracted widespread interest owing to their potential in wearable electronics, whereas their electromechanical performance, cost, and comfort remain main challenges. Here, we report a liquid metal core-shell fiber strain sensor that demonstrates ease of manufacturing, environmental friendliness, cost effectiveness, and suitability for large-scale production. It also exhibits a high aspect ratio, great softness, extraordinary flexibility, and long manufacturing length to wrap around the human body, enabling it for stretchable smart wearable applications. The sensor can withstand extreme tensile strain up to 1,200% without significant sensing performance degradation. It exhibits excellent static and dynamic characteristics, including high conductivity, wide working strain range, good sensitivity, low strain detection limit, high resolution, low hysteresis as low as 0.03%, response time of less than 20 ms, high repeatability, and good durability. Finally, experiments where it is incorporated in smart fabrics further validate its potential for real-time monitoring in healthcare and physiological movement applications.