Fiber‐Shaped, Stretchable Strain Sensors with High Linearity by One‐Step Injection Molding for Structural Health Monitoring

Abstract Fiber‐shaped strain sensors have attracted considerable attention due to their exceptional stretchability, conductivity, and flexibility, making them promising for applications in wearable electronics, smart textiles, and structural health monitoring. However, most reported ones based on elastic conductive fibers are fabricated by blending conductive materials with polymers, lacking effective encapsulation to resist environmental interferences such as dust and water. Inspired by the myelin sheath of nerve fibers, a fiber‐shaped, stretchable strain sensor featuring an elastic silicone tube is developed as the encapsulation layer and a conductive hybrid film as the sensing layer. The difference in rebound hysteresis capacity between the silicone tube and the hybrid film effectively enhances the sensor's recovery after stretching. Experimental results demonstrate that the sensors exhibit a linearity of up to 0.9958, a stretchability of 100% strain, and outstanding cyclic stability over 7 000 loading‐unloading cycles. Furthermore, the sensor demonstrates multi‐functionality in monitoring strain, temperature, and pressure while maintaining robust water and dust resistance. Application tests on large‐scale bridges and agricultural greenhouses have validated its effectiveness in structural health monitoring, showcasing the significant potential for use in health monitoring systems. The sensor's environmental resilience facilitates its deployment in real‐world scenarios by minimizing interference from external factors.