Fabrication and characterization of thin piezoelectric β-poly(vinylidene fluoride) films

The polymer polyvinylidene fluoride (PVDF) has four phases, each characterized by different molecular configurations of the polymer chains. In its beta phase it arranges in an all-trans configuration with dipolar symmetry, exhibiting piezoelectric effects. During the production of thin PVDF films by spin-coating, the polymer chains are not aligned and the dipoles are not oriented. To achieve the desired piezoelectric behavior, it is necessary to optimize both the chain alignment and the dipole orientation processes. We here present an easy procedure to maximize the percentage of the beta phase in the polymer production. The efficiency and reliability of such method has been assessed through Fourier-Transform Infra-Red and Raman spectroscopies, while the morphological differences of the two phases have been analyzed through Scanning Electron Microscopy. The results confirm the efficiency of this method.