Preparation and Properties of Poly(vinylidene fluoride) Multilayer Films

Along with the fast development of electronics. the demands of portable electronics and wireless sensors are growing rapidly. The need for self-powering materials capable of powering the electrical devices attached to them is increasing. The piezoelectric effect of polyvinylidene fluoride (PVDF) can be used for this purpose. PVDF has a special crystal structure consisting of a beta-phase that can produce piezoelectricity. In this paper, multilayer PVDF films were fabricated to increase the beta-phase content. A solution of 10% concentration N,N-dimethylacetamide (DMAc) in PVDF (PVDF/DMAc) was used to fabricate the films via spin coating technique with the following optimum process parameters: a spin rate of 850 rpm, spin time of 60 s, drying temperature of 60 degrees C, and drying time of 30 min. Compared with single-layer PVDF films, the multilayer films exhibited higher beta-phase content. The beta-phase content of the films increased gradually with increasing number of layers until 4. Maximum ratio of beta-phase content was 7.72.