Study on flexible large-area Poly(vinylidene fluoride)-based piezoelectric films prepared by extrusion-casting process for sensors and microactuators

Poly(vinylidene fluoride) (PVDF)-based film is a typical kind of piezoelectric films with wide applications, which is mainly prepared by the casting process. It is difficult to obtain large-area film and realize continuous fabrication. In this paper, Firstly, PVDF/PZT@105(lead zirconate titanate)/GO(graphene oxide) composite films with various GO contents were prepared via the casting process, and through comparison among the dielectric and mechanical properties , the optimum GO addition amount was determined. Subsequently, PVDF-based piezoelectric film(PVDF/PZT@105/GO)was prepared via the extrusion-casting process. Comparison between the composite films prepared by two different processes were taken. Note that the extrusion-casting process is favorable for obtaining superior properties such as higher density, dielectric constant, breakdown strength , and piezoelectric coefficient. Besides, during the exploration of the polarization technology it is found that the improvement of polarization field intensity tends to be is the most important factor affecting the piezoelectric properties of the film. The piezoelectric coefficient ( d 33 ) of PVDF/PZT@105/GO film prepared by the extrusion-casting process can reach 26 pC/N. Finally, the electrodeformation effect of the composite film was studied, obtaining the electromechanical strain up to 2%, which is much bigger than the piezoelectric ceramics ever been reported and can be used in the microfluidic field.