High pressure elastic and sensitivity PV/rGO/VF composite flexible sponge for intelligent environmentally friendly and physiological monitoring

Purpose This study aims to develop a flexible composite sponge sensor capable of simultaneously detecting pressure and physiological signals, addressing the limitations of earlier graphene-based flexible sensors, which have primarily focused on pressure detection alone. The goal is to enhance the application potential of such sensors in intelligent wearable technology, including human motion tracking, health monitoring and electronic skin. Design/methodology/approach A pressure-flexible composite sponge sensor was prepared using polyvinylidene fluoride (PVDF), viscose nonwoven fabric and graphene oxide (GO) through a simple and cost-effective method. High-pressure electrospinning was employed to inhibit the a-crystalline phase of PVDF while promoting the transformation to the ß-crystalline phase. High-temperature oxidation–reduction was used to improve the crystallinity of ß-phase crystals, enhancing the conductivity of the PVDF/reduced GO/viscose fiber/polydimethylsiloxane (PV/rGO/VF/P) sponges. The effect of GO mass ratio on thermal stability, weight loss, and resistance sensitivity was investigated. Findings The results showed that high-pressure electrospun PVDF promoted the transformation of diffraction peaks into the ß-crystalline phase, and high-temperature oxidation–reduction improved the crystallinity of ß-phase crystals, enhancing the conductivity of the composite sponges. Increasing the GO mass ratio improved the thermal stability and resistance sensitivity of the flexible composite device while reducing weight loss. The composite sponge exhibited the most sensitive electrical properties when compressed to 40% and could fully recover under 60% compression. The addition of viscose fiber enabled the composite sponge to precisely and sensitively detect sweat or glucose levels. Originality/value This study presents a novel approach to fabricating a pressure-flexible composite sponge sensor that integrates pressure sensing with physiological signal detection, a capability lacking in previously reported graphene-based flexible sensors. The use of high-pressure electrospinning and high-temperature oxidation–reduction to enhance the ß-crystalline phase and conductivity of PVDF, combined with the incorporation of viscose fiber for sweat and glucose detection, represents a significant advancement in the design of ergonomic, physiologically monitoring smart wearable devices. This innovation expands the application potential of 3D graphene-based nanosponges in intelligent wearable technology.