Flexible Piezoelectric Chitosan and Barium Titanate Biocomposite Films for Sensor Applications

There is currently a demand for flexible biomedical sensors. Characteristics as soft, thin, elastic, flexible and comfortable to the contact with skin should be matched with performance and ultimately made of sustainable, and biocompatible materials. In this work, chitosan as a flexible biodegradable polymeric matrix was combined with ferroelectric BaTiO3 particles obtained by hydrothermal synthesis to prepare flexible films. The biocomposites have high flexibility and the addition of particles improves the elasticity of pristine chitosan films. Of relevance towards the targeted application, the biocomposites exhibit a better resistance to water than chitosan. The dielectric permittivity increases with the addition of BaTiO3 particles. The observation of d(33) and d(15) by PFM, confirms the presence of piezoelectric domains corresponding to the location of BaTiO3 particles. These results contribute to the understanding of the role of functional oxides on the chemical and physical behavior of biobased polymers, creating opportunities to design optimized and more sustainable flexible piezoelectric sensor films.