Flexible Piezoelectric Nanogenerator Based on PVDF with Inserted Metal–Organic Framework-Derived ZrO₂-Graphene Nanoplatelets

Here, we have reported the fabrication of a wearable, flexible piezoelectric nanogenerator (PENG) based on PVDF nanocomposites where graphene nanoplatelets (GNPs) inserted into metal–organic framework (MOF)-derived ZrO2 (ZrO2-GNP) are used as a piezoelectric filler for β-phase stabilization of the PVDF polymer. The MOF route is suitable in improving the surface area of the ZrO2 resulting in better chemical interaction between the polymer matrix and the filler. In addition, the GNP improves the conductivity of the nanocomposites along with the device performance. The as-fabricated device with the highest loading of 5 wt % ZrO2-GNP in PVDF shows the highest open-circuit voltage of ∼60 V and short-circuit current of ∼2.2 μA under human finger imparting (F ∼15.5 N). Also, under a piezo-tribo-imparting machine (F ∼2.31 N), it shows an output voltage of ∼35 V. The highest power density obtained from the PENG is ∼40 μW/cm2, which is the adequate amount for powering up portable electronic devices like LEDs, calculators, wristwatches, etc. This PENG is also suitable for various kinds of applications, as it can generate voltage from various kinds of mechanical biomechanical forces.