The present work highlights an attempt of fabricating a nanocomposite by the addition of multi-walled carbon nanotubes (MWCNTs) as a third phase into flexible ZnO–poly(vinylidene fluoride) (ZnO–PVDF) composites. MWCNTs played a very important role in distributing ZnO fillers in the PVDF matrix more homogeneously and increased the connection capability. Enhancement of the piezoelectric phase, dielectric permittivity, ferroelectric polarization, energy storage density and mechanical energy harvesting performance of ZnO–PVDF composites after the addition of MWCNTs was confirmed from the respective characterization studies. The sensing capability was demonstrated by the generation of ∼22 V ac output voltage through the application of human finger tapping on 15 wt% ZnO and a 0.1 wt% MWCNT-loaded PVDF (15PZNT) based composite film. The rectified voltage from the fabricated 15PZNT film was used to charge a 10-μF capacitor up to ∼3 V which was used for the illumination of 30 commercial LEDs. The maximum power density from the film was found to be 21.41 μW cm⁻² at 4 MΩ load resistance. The effect of the addition of MWCNTs was also verified by simulation using COMSOL Multiphysics software.

In the present work, we report the enhanced dielectric, ferroelectric, energy storage and energy harvesting performance of a citrate-gel synthesized Bi _1−x Ba _x FeO ₃ ( x = 0, 0.05, 0.10) incorporating poly(vinylidene fluoride) (PVDF) matrix.

Here, we introduce a 2D metal-organic framework (MOF) into the poly(vinylidene fluoride) (PVDF) matrix, which has been comparatively less explored in this field. Highly 2D Ni-MOF has been synthesized in this regard via hydrothermal route and has been incorporated into PVDF matrix via solvent casting technique with ultralow filler (0.5 wt%) loading. The polar phase percentage of 0.5 wt% Ni-MOF loaded PVDF film (NPVDF) has been found to be increased to ~85% from a value of ~55% for neat PVDF. The ultralow filler loading has inhibited the easy breakdown path along with increased dielectric permittivity and hence has enhanced the energy storage performance. On the other hand, significantly enriched polarity and Young’s Modulus has helped in improving its mechanical energy harvesting performance, thereby enhancing the human motion interactive sensing activities. The piezoelectric and piezo-tribo hybrid devices made up of NPVDF film have shown improved output power density of ~3.26 and 31 μW/cm² compared to those of the piezoelectric and piezo-tribo hybrid devices comprising of neat PVDF (output power density ~0.6 and 17 μW/cm², respectively). The developed composite can thus be considered an excellent candidate for multifunctional applications.

Along with enhanced dielectric permittivity and suppressed dielectric loss, PVDF-ZnO@ZnSnO ₃ films showed simultaneous enhancement in electrical energy storage density and storage efficiency compared to PVDF-ZnSnO ₃ composites.

Hydroxylation of a BiFeO₃ filler improved the dielectric permittivity, energy storage density and mechanical energy harvesting performance along with reduced dielectric loss of its PVDF based composites compared to that of an untreated BiFeO₃ filler.