Double Raschel-Structured Fabric Based on SnTiO3 Nanorod-Embedded 8-Petal Cross-Section PVDF Fibers for an Advanced Disaster Warning System

Abstract

This study investigates both structural and non-structural effects on the piezoelectric performance of polyvinylidene fluoride (PVDF) fibers, focusing on the impact of double Raschel fabric components. It identifies key factors influencing performance, with emphasis on optimizing fiber cross-sectional shape, specifically an eight-petal structure. This structure enhances piezoelectric output with an open-circuit voltage (Voc) of 41.28 V and short-circuit current (Isc) of 6.140 µA due to its large surface area. Incorporating 5% SnTiO3 nanorods as high-relative permittivity fillers results in maximum performance improvement. Structural optimization using double Raschel fabric with different spacer yarn lengths reveals that the 5 mm configuration provides the best performance, achieving a Voc of 92.80 V and Isc of 4.130 mA. The double Raschel structure has the most significant impact on piezoelectric performance, followed by the full transition of the structure to PVDF embedded with 5% SnTiO₃ nanorods. Modifying the spacer yarn composition plays a crucial role in enhancing Isc. The effect of air volume is found to be more dominant than that of the spacer yarn length. Notably, the optimized double Raschel structure fabrics demonstrate high durability as real-time landslide warning systems, capable of generating piezoelectric output with body motions and sending real-time warning messages via Bluetooth under simulated landslide conditions.