Friction, Adhesion, and Elasticity of Grahene Edges

Frictional, adhesive, and elastic characteristics of graphene edges are determined through lateral force microscopy. Measurements reveal a significant local frictional increase at exposed graphene edges, whereas a single overlapping layer of graphene removes this local frictional increase. Comparison of lateral force and atomic force microscopy measurements shows that local forces on the probe are successfully modeled with a verticaladhesioninthevicinityoftheatomic-scalegraphenestepswhichalsoprovidesanewlow-loadcalibration method. Lateral force microscopy performed with carefully maintained low-adhesion probes shows evidence of elastic straining of graphene edges. Estimates of the energy stored of this observed elastic response is consistent with out-of-plane bending of the graphene edge.