(328a) A Model for Nanoscale Friction on Few Layer Graphene

Sesha Hari Vemuri, Pil Seung Chung, Robert Smith and Myung S. Jhon

One of the most researched nanoscale materials is graphene and its thermal, mechanical, chemical, and electrical properties.  The effect of the dimensional characteristics of graphitic materials on their tribological properties was elucidated in Lee et al.’s work on the frictional characteristics of atomically thin materials, with a particular emphasis on few layer graphene (FLG) where atomic force microscopy (AFM) were utilized to reveal the effect of the number of layers on the frictional response. 

In the present work, we constructed a nano-friction model for the first time to compare our result with the experimental friction force on FLG materials for the entire range of the data available [1].  In contrast to the bulk material, the FLG exhibits a sloping frictional force profile over short AFM scanning distances.  We develop a model to replicate the tilted friction phenomenon as a function of the number of layers.  Our model compares well with the experimental friction profile of FLG and demonstrates the ability of our model to reveal the transition from 2-D to 3-D tribological characteristics.

[1] C. Lee, Q. Li, W. Kalb, X.K. Liu, H. Berger, R.W. Carpick, J. Hone, Science 328, 76 (2010).