Superhydrophobic pressure-responsive pressure sensors based on an inner–outer synergistic conductive network of GAF/PDMS

Abstract

Flexible sensors have attracted widespread attention due to their potential applications in wearable technology and motion detection. We have used hydrothermal reduction and sacrificial template methods to prepare a superhydrophobic pressure-sensitive sensor with an internal and external synergistic conductive network based on graphene fragments (GAF) and polydimethylsiloxane (PDMS) sponge. The van der Waals forces between graphene and PDMS enable good combinations of PDMS with GAF and rGO. The combination of flexible PDMS with rigid GAF results in the sponge having good mechanical properties, maintaining good cyclic stability after 1000 loading–unloading cycles. After reduction, a portion of the reduced graphene oxide exists in the form of GAF within the sponge, while another portion exists in the form of rGO particles attached to the surface of the sponge, forming a synergistic conductive network, enhancing the electrical performance of the sensor, with a sensitivity of up to 6.9 kPa⁻¹. Furthermore, the sensor can effectively distinguish different movements of the human body, enabling motion detection. Our research results provide a feasible solution for the manufacturing of high-performance superhydrophobic flexible pressure sensors, which can still function normally even in humid environments.