▎ 摘　　要

Promoted by the demand for wearable devices, graphene has been proved to be a promising material for potential applications in flexible and highly sensitive strain sensors. However, low sensitivity and complex processing of graphene retard the development toward the practical applications. Here, an environment-friendly and cost-effective method to fabricate large-area ultrathin graphene films is proposed for highly sensitive flexible strain sensor. The assembled graphene films are derived rapidly at the liquid/air interface by Marangoni effect and the area can be scaled up. These graphene-based strain sensors exhibit extremely high sensitivity with gauge factor of 1037 at 2% strain, which represents the highest value for graphene platelets at this small deformation so far. This simple fabrication for strain sensors with highly sensitive performance of strain sensor makes it a novel approach to applications in electronic skin, wearable sensors, and health monitoring platforms.