All‐organic shell–core PVDF/PMMA composite fiber films with enhanced piezoelectric performance for flexible sensing and energy harvesting.

The demand for self‐powered sensing technology and energy harvesting system necessitates high‐performance and flexible piezoelectric materials. This paper presents a novel approach utilizing coaxial electrospinning to fabricate all‐organic PVDF/PMMA piezoelectric fiber films with a shell–core structure. The resulting fiber films, cut into 2 × 2 cm2 square pieces and hot‐pressed every three pieces, demonstrate enhanced piezoelectric properties while retaining high flexibility. The interaction between the CO bonds in the PMMA polymer and the CH2 in PVDF promotes the arrangement of F atoms in PVDF, enhancing the content of the piezoelectric active phase. Additionally, the coaxial electrospinning process fosters vertically oriented hydrogen bonds between PVDF and PMMA, augmenting cross‐linking and improving mechanical properties. Notably, when the PVDF to PMMA layer volume ratio is 5:1, the piezoelectric coefficient (|d33|) of the composite fiber film exhibits a significant 60% increase from 10 pC N−1 in neat PVDF to 16 pC N−1. This research holds substantial promise for applications in self‐powered sensing and energy harvesting piezoelectric materials. [ABSTRACT FROM AUTHOR]