Highly sensitive flexible strain sensor based on GSB-enhanced three-dimensional graphene composite

High-sensitive flexible strain sensor is a key device for artificial intelligence and wearable electronics. Specifically, the aim of this work is to investigate the design of graphene-SiO2 balls enhanced (GSB-enhanced) threedimensional (3D) graphene foam (GSBF) electrode structure, which is combined with flexible material polydimethylsiloxane (PDMS) for a highly sensitive strain sensor. The GSBF/PDMS strain sensor presents excellent performances: stretching ratio of 50%, response time of less than 128 ms and high sensitivity (the strain coefficient GF = 103, in variation range of 0-13% strain), due to its unique mechanical and conductive properties. Moreover, a high stability of more than 300 loading-unloading cycles is achieved without dramatic resistance increment. Our sensors could be used in several wearable applications including monitoring finger movement, the pulse ratio, the strain of the knee joint in patellar reflex and the movements of elbow, wrist, sole etc. Our research illustrates the potential abilities in the fields of robotic systems, healthcare and flexible electronics applications with less cost and more accessible.