Structure and Thermomechanical Properties of Polyvinylidene Fluoride Film with Transparent Indium Tin Oxide Electrodes

Abstract

This paper is devoted to the study of the structure and thermomechanical properties of PVDF-based ferroelectric polymer film. Transparent electrically conductive ITO coatings are applied to both sides of such a film. In this case, such material acquires additional functional properties due to piezoelectric and pyroelectric effects, forming, in fact, a full-fledged flexible transparent device, which, for example, will emit a sound when an acoustic signal is applied, and under various external influences can generate an electrical signal. The use of such structures is associated with the influence of various external influences on them: thermomechanical loads associated with mechanical deformations and temperature effects during operation, or when applying conductive layers to the film. The article presents structure investigation and its change during high-temperature annealing using IR spectroscopy and comparative results of testing a PVDF film before and after deposition of ITO layers for uniaxial stretching, its dynamic mechanical analysis, DSC, as well as measurements of the transparency and piezoelectric properties of such structure. It is shown that the temperature-time mode of deposition of ITO layers has little effect on the thermal and mechanical properties of PVDF films, taking into account their work in the elastic region, slightly reducing the piezoelectric properties. At the same time, the possibility of chemical interactions at the polymer–ITO interface is shown.

Optimizing solvent dipole moment enables PVDF to improve piezoelectric performance

“…Flexible piezoelectric polymers are considered to be the most hopeful elements in the next generation of flexible electronic skins, pressure sensors, energy harvesters, and self-powered miniaturized devices [1][2][3]. Among various promising alternatives, polyvinylidene fluoride (PVDF) is considered to be the most competitive piezoelectric polymer [4]. However, their dielectric permittivity (ε) and piezoelectric coefficient (d 33 ) are relatively low compared to ceramics [5,6].…”