Highly sensitive self-powered piezoelectric poly(vinylidene fluoride)-based nanofibrous mat containing microporous metal-organic framework nanostructures for energy harvesting applications

Developing highly sensitive flexible piezoelectric sensor for wearable electronic devices have received considerable attention due to their promising application in physiological monitoring. Therefore, many research studies are conducted to enhance the piezoelectric response of poly(vinylidene fluoride) (PVDF)-based membrane. In this work, we present a novel flexible piezoelectric PVDF-based sensor with high-pressure sensitivity induced by the incorporation of microporous metal-organic framework (MOF) particles. Scanning electron microscopy images indicated the formation of uniform and bead-free PVDF/MOF nanofibrous composite with an average diameter of 173-241 nm. In this design, the microporous MOF crystals extremely enhanced the polar beta-phase content of PVDF nanofibers by 20% without significant loss in its flexibility and synergistically promoted the piezoelectric performance of PVDF-based sensor. The PVDF nanofibers containing 1 wt% MOF crystals showed a peak-to-peak voltage of 3.84 V under an applied force of 2.5 N, which was superior to that of pristine PVDF nanofibers by 32%. Furthermore, the practical application of the developed PVDF/MOF nanofiber-based piezoelectric sensor was demonstrated for detecting human activities, showing a maximum output voltage of 2.08 V (for finger tapping), 5.92 V (for hand punching), and 20.66 V (for heel strike). The self-powered and highly sensitive PVDF/MOF nanofiber-based piezoelectric sensor also exhibits excellent long-term working stability with no obvious responsivity attenuation. The results of this work provide new insights for the development of next-generation piezoelectric sensors and energy harvesting systems.Graphical abstractA novel flexible piezoelectric PVDF-based nanogenerator with high-pressure sensitivity induced by the incorporation of microporous MOF particles. The piezoelectric response of the developed PVDF/MOF nanogenerator indicated superior output voltage and sensitivity than most of the reported PVDF-based nanogenerators.

Automated summary

A novel flexible piezoelectric PVDF-based nanogenerator with high-pressure sensitivity induced by the incorporation of microporous MOF particles is developed. The developed PVDF/MOF nanogenerator exhibits superior output voltage and sensitivity compared to most reported PVDF-based nanogenerators.