In this study, for the first time we report the combined impact of electrospinning, carbon nanofiber (CNF) addition and electrical poling in the polyvinylidene fluoride (PVDF) polymer on its beta phase transition and enhancement of piezoelectric effect. CNF (0.25%, 0.5%, 0.75% and 1% (w/w)) dispersed PVDF electrospun nanofibers were characterized for their morphology, functional group and electrical properties using SEM, FTIR, Raman, XRD and impedance analyzer. The developed nanofibers showed promising results in beta phase transition and 0.5% (w/w) CNF filled PVDF nanofibers were found to possess high beta phase crystals compared to other studied samples. After 30 V/mu m electrical polling at 30 degrees C for 6 h, piezoelectric property of 0.5% (w/w) CNF based nanocomposite nanofiber showed highest open circuit voltage and short circuit current (5.8 +/- 0.17 V and 1.2 +/- 0.1 mu A, respectively, at 35 mu m compression). In future, these matrices can be used for development of affordable and nontoxic energy converters in biomedical wearable sensors. (C) 2019 Elsevier B.V. All rights reserved.