Polyvinylidene Fluoride Based Breathable Membranes with Core–Sheath Structure for Multifunctional Piezoelectric Sensors
Youlei Tu, Qiang Feng, Meng Shi, Shaoyun Guo, Xiaobao Tian, Jiabin ShenAbstract
The widespread practical applications of piezoelectric fluoropolymer-based materials are hampered by low piezoelectric coefficients (d33) and complex polarization processes. Herein, the biomimetic core–sheath structure constructed through the electrostatic self-assembly process enables the dipoles of polyvinylidene fluoride/glycine hydrochloride (PVDF/Gly-HCL) fibers to form a long-range ordered distribution via the interfacial suppressing effect. This effect significantly improves the piezoelectricity. PVDF/Gly-HCL fibers doped with 0.5 wt % Gly-HCL not only have ultrahigh β-phase content (Fβ = 98.2%), but also have the highest d33 (67.4 pm V–1). In addition, when the external force field is increased, the fibers show a macroscopic orientation distribution. Additionally, the optimized PVDF/Gly-HCL breathable membranes are capable of a fast response time (24 ms), high sensitivity (1.73 V kPa–1), long-term stable durability (about 10,000 cycles, <2% fluctuation), and excellent breathability. This work provides a scalable and universal road for the preparation of flexible, breathable, and high-performance PVDF self-powered sensing systems.