Mechanical buckling induced periodic kinking/stripe microstructures in   mechanically peeled graphite flakes from HOPG
  Mechanical exfoliation is a widely used method to isolate high quality graphene layers from bulk graphite. In our recent experiments, some ordered microstructures, consisting of a periodic alternation of kinks and stripes, were observed in thin graphite flakes that were mechanically peeled from highly oriented pyrolytic graphite (HOPG). A theoretical model is presented in this paper to understand the formation of such ordered microstructures, based on elastic buckling of a graphite flake being subjected to a bending moment. The width of the stripes predicted from this model agrees reasonably well with our experimental measurements. 
Manrui Ren, Ze Liu, Quan-shui Zheng, Jefferson Zhe Liu
cond-mat.mtrl-sci