Preparation and performance study of non-metallic core piezoelectric optical fiber

In response to the problem of insufficient toughness and limited piezoelectric performance of traditional metal core piezoelectric fibers (MPF) under complex loads, this study proposes the use of dual thermal shrinkage method to prepare Kevlar core piezoelectric fibers, replacing the metal core with lightweight and high toughness Kevlar fibers to construct a new non-metallic core piezoelectric fiber system. The stress-strain curve test shows that the toughness and tensile strength of Kevlar core are significantly improved compared to metal core, with toughness being 2.22 times that of metal core and tensile strength being 7.8 times that of metal core, effectively solving the problem of interface stress concentration caused by rigid support in traditional metal core. During the preparation process, the synergistic thermal shrinkage effect of thermoplastic [polyvinylidene fluoride (PVDF)] tube and silicone tube was utilized to achieve tight bonding and uniform coaxiality of the core-shell structure. Performance testing shows that the prepared Kevlar core piezoelectric fibers have excellent global dynamic sensing capabilities, with a deviation of less than 5.21% between the average voltage at each point and the total average voltage; The piezoelectric performance test shows that under the same load and impact rate conditions, its peak voltage can be increased by up to 25.41% compared to traditional metal core fibers. This method combines the advantages of simple process, low equipment cost, and efficient production, providing a lightweight and high-performance piezoelectric material solution for the fields of flexible sensing, wearable devices, and structural health monitoring.