Dual‐Mode Wearable Strain Sensor Based on Graphene/Colloidal Crystal Films for Simultaneously Detection of Subtle and Large Human Motions

Abstract

AbstractWearable strain sensors with high sensitivity and broad sensing ranges to detect both subtle and large human motion are highly desirable in health monitoring systems. Here, a novel, dual‐mode strain sensor based on the reduced graphene oxide (rGO)/polydimethlsiloxane (PDMS) film adhered to micropatterning elastomer colloidal crystal film is proposed to realize these goals. The rGO/PDMS film is designed for detecting subtle human motion via its resistance change, while the colloidal crystal film is used for detecting large human motion via its simple colorimetric changes or reflection peak shifts and simultaneously as a microstructured substrate for graphene film to improve their sensitivity. Investigation of their detection ability displays that the colloidal crystal film exhibits a wide sensing range up to 68.2% strain and the rGO/PDMS film demonstrates a high gauge factor value of 4.78 within 30% strain with rapid response time and excellent reversibility. Such superior performance endows the dual‐mode sensor for detecting various large human joint movements and subtle human physiological motions. This research provides new insights into the design and fabrication of high‐performance strain sensor for full‐range human motions' detection and the proposed sensor has great potential for application in human motion recognition and healthcare monitoring.