Vanadium disulfide-incorporated polymer nanocomposites for flexible piezoelectric energy generators and road safety sensors

Abstract

Piezoelectric materials have attracted considerable attention in the field of flexible electronics owing to their ability to convert mechanical strain into electrical energy. The advancement of piezoelectric flexible devices has created new opportunities for a wide range of applications including energy harvesting and sensing. In this work, a new combination of polymer nanocomposites as piezoelectric materials for energy harvesting and pressure sensing was introduced. A facile technique is reported to demonstrate a flexible and outstanding piezoelectric nanogenerator by using a layered transition metal dichalcogenide, vanadium disulfide (VS₂), as a nanofiller material embedded in a poly(vinylidene fluoride) (PVDF) polymer. The piezoelectric property of the PVDF polymer was enhanced by the addition of VS₂ via aligning the PVDF molecule into its most favourable piezoelectric β-phase. The optimization of the polymer nanocomposite was carried out by different characterisations of the materials and fabricated devices. The working prototype of an energy harvesting pressure sensing device with an optimized polymer nanocomposite (P/VS₂ (0.25)) was developed with polymer packaging. A maximum output voltage of ∼83 V and a maximum open circuit current of ∼52 μA were obtained, with an irregular biomechanical force of 7 to 8 N. The prototype device displayed an outstanding power of 2115.25 μW and a power density of 114.4 μW cm⁻² when short-circuited with a load resistance of 1 MΩ. Further, the prototype device was used to demonstrate energy generation, wearable and storage applications. The real-time demonstration as a road safety and smart door sensor proves that the new polymer nanocomposite will be a potential candidate for developing highly efficient, flexible and sensitive energy harvesting and pressure sensing devices.