Highly stable strain sensor using rGO decorated with multi-component alloy nanoparticles for human motion monitoring

Wearable, flexible devices have garnered widespread attention in the realm of human motion and life activity detection. Currently, the development of simple, green, and easily scalable methods for fabricating strain sensors still presents significant challenges. In this study, we successfully modified the surface of reduced graphene oxide (rGO) with SnCuNiIn multi-component alloy nanoparticles (MCA NPs), with an average size of 13.29 nm, utilizing a green and facile microwave heating approach. Leveraging the SnCuNiIn MCA NPs/rGO powder, we formulated a conductive ink based on water and ethylene glycol, which, when screen-printed, yielded conductive patterns with a minimum resistivity of 4.366 mΩ·cm. Strain sensors produced using this ink demonstrate exceptional performance, demonstrating favorable resistance change rates during a single bending process that meets practical application requirements, and enduring 5000 bending cycles with a resistance change of less than 5%. These sensors exhibited a high gauge factor (GF_max = 52.7) and outstanding cycling stability. Lastly, strain sensors are employed to monitor human normal life activities and motion states, showcasing significant potential for application in wearable electronic products.