Versatile Core–Sheath Yarn for Sustainable Biomechanical Energy Harvesting and Real‐Time Human‐Interactive Sensing.

The emergence of stretchable textile-based mechanical energy harvester and self-powered active sensor brings a new life for wearable functional electronics. However, single energy conversion mode and weak sensing capabilities have largely hindered their development. Here, in virtue of silver-coated nylon yarn and silicone rubber elastomer, a highly stretchable yarn-based triboelectric nanogenerator (TENG) with coaxial core–sheath and built-in spring-like spiral winding structures is designed for biomechanical energy harvesting and real-time human-interactive sensing. Based on the two advanced structural designs, the yarn-based TENG can effectively harvest or respond rapidly to omnifarious external mechanical stimuli, such as compressing, stretching, bending, and twisting. With these excellent performances, the yarn-based TENG can be used in a self-counting skipping rope, a self-powered gesture-recognizing glove, and a real-time golf scoring system. Furthermore, the yarn-based TENG can also be woven into a large-area energy-harvesting fabric, which is capable of lighting up light emitting diodes (LEDs), charging a commercial capacitor, powering a smart watch, and integrating the four operational modes of TENGs together. This work provides a new direction for textile-based multimode mechanical energy harvesters and highly sensitive self-powered motion sensors with potential applications in sustainable power supplies, self-powered wearable electronics, personalized motion/health monitoring, and real-time human-machine interactions.