Graphene/MXene@Polyurethane sponge flexible piezoresistive sensor with high sensitivity, stability and variability

Flexible sensors have garnered significant attention due to their potential applications in monitoring human physiological signals, wearable devices, and healthcare. In this study, the dip coating method was employed to fabricate a flexible piezoresistive pressure sensor based on graphene/MXene@polyurethane (PU) sponge. Leveraging the porous structure of PU sponge and the high conductivity and synergistic effects of graphene and MXene additives, this sensor can effectively monitor both small strain activities, such as speech recognition, and large strain activities, like elbow bending. Notably, this flexible pressure sensor exhibits high sensitivity (2.68 kPa −1 in the 0~15 kPa range), high stability (withstanding 8000 load cycles), a short response time (61 ms), and a wide detection range (0-100 kPa). These features endows the sensor with outstanding multifunctionality, making it highly adaptable and broadly applicable for monitoring human health vital signals, as well as for detecting motion and sound vibration.