A wearable dual-mode strain sensing yarn: Based on the conductive carbon composites and mechanoluminescent layer with core-sheath structures

Abstract

Yarn or fiber has the advantages of flexible processing, comfortable wearing, good service life, high feasibility of mass production. In recent years, the wearable strain sensor based on yarn or fiber has attracted wide attention. However, most of the previous research work is based on a single electrical signal or energy conversion sensor, which greatly reduces the application range of strain sensor. Therefore, multi-mode sensing under stress application conditions is particularly important promoting the development of new materials. By combining resistive stress sensing with mechanical luminescence sensing, the two-mode strain sensing yarn is prepared and applied in wearable applications. The results show that the tensile strength of core-shell yarn can reach 180% and the surface brightness can reach the visual level. When the carbon concentration in the core yarn is 40%, the corresponding range is small and the resistance increases from 3 MΩ to 5MΩ. The doped luminescent powder has a strong luminescent peak at 578 nm and a small luminescent peak at 493 nm under the action of stress. These properties solve the problem of non-stretching of conductive yarns and can better reflect the magnitude of stress. It also has good application prospects in motion detection, health care, human-computer interaction, artificial intelligence and so on.