Measurements of mechanical properties and number of layers of graphene from nano-indentation

In this paper, we introduce an approach to simply and effectively determine the mechanical property and number of layers of graphene simultaneously from one indentation by using an instrumented nano-indenter. The results reveal that the elastic modulus of a single layer graphene is 0.89 TPa after correction of the effect of substrate, which is coincident to the experimental and theoretical data from other researches. In addition, it is found that there exist a linear relationship between the number of layers and the hardness of graphene, which provide a novel and also effective method for judging the number of graphene layers. (C) 2012 Elsevier B.V. All rights reserved.