Integrated Janus Meta-Fabric via an Interlock Stitch Knitted Structure for Marginal Physiological Signal Monitoring

Fabric-based wearable sensors for athletic performance monitoring have emerged as a focal point of research in recent times. For runners, tracking both respiration and stride is immensely advantageous, as these parameters jointly indicate an individual’s running performance. However, conventional wearable sensors incorporated into athletic apparel often compromise on flexibility, elasticity, and breathability, thereby affecting comfort and athletic performance. Additionally, they may be susceptible to external disturbances and can induce discomfort due to a strong foreign body sensation, coupled with restricted measurement capabilities. To address these challenges, we introduce a Janus fabric interlock stitch knitted triboelectric nanogenerator (ISK-TENG). The unique interlock stitch knitted design of the ISK-TENG ensures exceptional stretchability and breathability. Within the ISK-TENG, two triboelectric fabric layers are seamlessly integrated to form a Janus structure, which comes into contact under stretching or compression forces and returns to its original detached state upon the removal of external force. In lateral stretching mode, the ISK-TENG achieves an electrical output of 160 V and 130 nA; in vertical pressing mode, it delivers an output of 6 V and 15 nA. Furthermore, by integrating the ISK-TENG into clothing, we have developed an intelligent trouser featuring a one-body ISK-TENG system. This trouser is capable of monitoring human movement and respiration across various breathing patterns. Our work presents an innovative approach to concurrently monitor both large body movements and subtle respiratory signals, thereby enhancing the athletic performance of runners.