Effective bulk modulus elastographic study of concentration-tunable PVDF-V2O3 electrospun composite films

Poly(vinylidene fluoride) (PVDF) thin films embedded with varying concentrations of vanadium(III) oxide (V2O3), 0, 5, 15, and 25% by weight, were fabricated to investigate their structural, mechanical, and piezoelectric characteristics. All films were synthesized using identical solvent systems and electrospinning parameters to ensure uniform processing conditions and enable direct comparison. Effective bulk modulus elastography (EBME) was employed to characterize the dynamic bulk modulus of the films, revealing compositional dependence of mechanical stiffness linked to microstructural modifications. The piezoelectric response, measured via the d33 coefficient, exhibited significant enhancement in the PVDF–V2O3 (5%) film relative to both the pristine PVDF and higher oxide loading variants. This improvement suggests optimized interfacial polarization and matrix filler interaction at low filler concentrations. Furthermore, variations in V2O3 content led to noticeable differences in film thickness and porosity, which in turn influenced both the elastic modulus and piezoelectric behavior. The results identify PVDF–V2O3 (5%) as a promising composition for enhanced piezoelectric sensing applications, offering a favorable balance of mechanical robustness and functional response.