Silver nanoparticles coated microcracked poly(styrene butadiene styrene)/graphene/carbon nanotube composite fiber for high performance strain sensing.

[Display omitted] • Conductive fiber was prepared via coaxial wet spinning and magnetron sputtering. • The microcracks and silver plating improved the sensing strain from 70% to 167%. • The SBS/Gr/CNTs/Ag fiber sensor has a very high gauge factor of 1669. In this study, a flexible strain sensor with high sensitivity and a wide working strain range was developed by employing a poly(styrene butadiene styrene) (SBS) matrix and carbon nanotubes (CNTs)/graphene (Gr) as the conductive filler via coaxial wet spinning. Microcracks were induced on the surface of the SBS/Gr/CNTs fibers through controlled mechanical stretching, followed by enhancing the conductive network through silver plating using magnetron sputtering. The results revealed that both the formation of the microcrack structure and silver plating significantly improved the strain sensing performance of the SBS/Gr/CNTs fibers. The formation of microcracks increased the maximum sensing strain from 70 % to 110 % with a high gauge factor of 902. Furthermore, with a silver sputtering duration of 5 min, the strain working range of the silver-plated SBS/Gr/CNTs fiber-based sensor increased to 167 %, accompanied by a significantly enhanced gauge factor of 1669. The SBS/Gr/CNTs/Ag fiber sensor also exhibited reliable stability and durability during repeated stretching-releasing cycles. Moreover, it demonstrated the ability to monitor human movements, including finger and wrist joint motions, as well as knee joint bending. These findings highlight the effectiveness of microcrack formation and silver plating in enhancing the strain sensing capabilities of SBS/Gr/CNTs fibers. The developed sensor holds great promise for various applications, particularly in monitoring human movements and structural deformation. [ABSTRACT FROM AUTHOR]