Electrospinning core-sheath piezoelectric microfibers for self-powered stitchable sensor

Abstract Owing to the limitations of two-dimensional devices such as easily damaged and airtight characteristics in practical applications, flexible fiber electronics which can narrow the gap between devices and wearable applications due to their unique stitchable function have been attracting tremendous attention nowadays. Here, this paper introduced a simple strategy for fabricating the piezoelectric microfiber with a novel core-sheath structure by directly electrospinning the poly(vinydene fluoride-trifluoroethylene) (P(VDF-TrFE)) onto the flexible conductive wire. Precise control of the fiber diameter and thickness of P(VDF-TrFE) functional layer can be achieved. Specifically, this stitchable fiber exhibits high sensitivity of 60.82 mV/N and excellent durability of 15000 cycles under positive compression, and finite element method (FEM) was carried out cooperating with practical experiment to analyze the stress and electric field distribution of piezoelectric fibers under both positive compression and bending modes through COMSOL software. The flexible stitchable fiber can bear various complex, even severe deformations such as bending and knotting, enabling itself to be woven into textile and further generate power and response when subjected to external deformation, which is of significance for the portable and wearable electronics that are expected to be breathable and comfortable. This work also offers a general and effective solution for the flexible and wearable electronic devices.