Effect of spatial structure and aggregation state of silk fibers in fabric on strain sensing performance and mechanism

Silk has attracted attention in the development of fabric-based sensors due to its structural controllability including fabrics, yarns, fibers, etc. Among them, the distribution of fibers in the yarn has a decisive effect on the conductive network. In this work, the characteristics and performance of four carbonized silk fabric-based strain sensors by adjusting the twist of the yarn were systematically characterized. On this basis, the fabric strain fracture process was explored in depth using optical electron microscopy, structural evolution simulation and finite element analysis to research the sensing mechanisms. The results indicated that the fabric sensors composed of twisted yarns had better sensitivity (GF of 6.3) and high linearity over a wide range of strains (0.996 under 0-300 %). In addition, the sensor had the advantages of fast response time (110 ms), and high durability (5000 cycles under multi-model strains). The sensors were also able to fulfill stable and sensitive responses under torsional and bending strains. Finally, a smart sports suit was developed based on this flexible strain sensor, which provided real-time collaborative feedback on movement and physiological signals in air and underwater. Undoubtedly, this smart amphibious sports suit has broad application prospects and values for wearable elec-tronic devices.