PVDF fibers were prepared via electrospinning with different electric field and rotating speed, respectively. The values of piezoelectric output of the devices assembled by PVDF fibrous membrane linearly fit with the product of the numerical values (C-EP, content of effective piezo-phase) of crystallinity and beta-phase proportion in electrospun fibers. With the optimized parameters of electric field (15 kV) and rotation speed (500 rpm) in electrospinning, the maximal output of 2.8 V and 1.32 mu A were obtained. The controllable crystal structure of PVDF and definite relationship between preparation parameters and piezoelectric behavior is beneficial for modulating the mechanical-to-electrical conversion in device. (C) 2018 Elsevier B.V. All rights reserved.