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 cm 2 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  CH 2 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 (| d 33 |) 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.