Graphene bilayer film responsive to ultraviolet, humidity, and temperature

Multimodal sensors are devices characterized by their ability to respond in various ways and simultaneously detect and differentiate environmental changes, which is of significant importance for research on multifunctional wearable sensors. However, the majority of current studies on multimodal sensors struggle to incorporate simultaneous light intensity detection. This paper presents a novel approach that utilizes graphene oxide to create bilayer films with varying oxygen content using a thermal reduction process, enabling simultaneous detection and differentiation of ultraviolet light, humidity, and temperature, while demonstrating excellent flexibility and self-powered capabilities. The proposed structure reveals that the oxygen functional groups within graphene oxide can induce proton generation in response to external environmental stimuli, facilitating rapid proton migration driven by the asymmetric charge distribution resulting from the variation in oxygen content between the bilayer films. This innovative operational mechanism may provide new insights for implementing electrical signal transmission using protons as charge carriers. Furthermore, this structure holds potential for the design of artificial electronic skin and other wearable devices, enabling rapid detection of multiple signals in complex environments.