High performance humidity sensors based on patterned graphene oxide films for real-time healthcare and environmental monitoring

Abstract Real-time monitoring in healthcare and environmental fields demands humidity sensors with high precision and fast response. Their development is constrained by challenges in scalable and controllable fabrication of patterned sensing films. This paper proposes a controlled fabrication method for patterned graphene oxide (GO) films by integrating substrate wettability regulation with a doctor-blading process, addressing the challenges in the scalable fabrication of high-precision humidity sensors. A wettability-confined strategy is employed to construct precise hydrophilic–hydrophobic interfaces on substrates, enabling the selective and uniform deposition of GO solutions without the ‘coffee-ring effect’. Systematic characterization confirms the method’s high controllability and material stability. Based on an equivalent circuit model, this study thoroughly analyses the influence mechanisms of key parameters—such as effective area and electrode spacing—on impedance and capacitance. The optimized sensor exhibits high sensitivity, low hysteresis, and ultrafast response/recovery times (0.36 s/0.32 s). Furthermore, the sensor is integrated into a wireless monitoring system for detecting environmental humidity, demonstrating its great potential in the monitoring of relative tidal volume variations and real-time human healthcare applications. This work provides a versatile and scalable strategy for fabricating high-performance patterned films for next-generation flexible electronics.