Unveiling friction mechanism in exfoliated graphene

In this study, we investigated the underlying mechanisms of friction in graphene, which have been far less studied compared to its electrical properties. We manipulated the surface energy of the substrate and compared the friction using lateral force microscopy techniques. Additionally, we observed frictional domains within monolayer graphene sheets, which exhibited multiple friction levels. Through a series of experiments, we directly identified these frictional domains along with their intrinsic ripple structures oriented in a uniaxial direction. We also discovered intriguing properties by varying the angle between the scan direction and the ripple direction.