Recent experiments reveal that a scanning tunneling microscopy (STM) probe tip can generate a highly localized strain field in a graphene drumhead, which in turn leads to pseudomagnetic fields in the graphene that can spatially confine graphene charge carriers in a way similar to a lithographically defined quantum dot (QD). While these experimental findings are intriguing, their further implementation in nanoelectronic devices hinges upon the knowledge of key underpinning parameters, which still remain elusive.
The current paper focuses on investigating deformation mechanism of graphene sheets in a graphene reinforced polyethylene (Gn–PE) nanocomposite. Classical molecular dynamics (MD) simulation was conducted on large Gn–PE systems. Different spatial arrangements of graphene sheets were considered in order to study the effect of nonlocal interaction among the graphenes. In all the cases 5% weight concentration of graphene was considered in order to prepare atomistic models for Gn–PE.
In armchair graphene sheets, crack propagates perpendicular to the applied strain, whereas crack propagation in zigzag sheets occurs at an angle to the straining direction. This occurs due to different bond structure along armchair and zigzag directions as shown in Fig. 1. Videos 1 and 2 show the fracture of armchair and zigzag sheets, respectively.
Fig. 1: Armchair and zigzag directions of graohene
A post-Doc position is available on a project on Ensemble Monte Carlo simulations of graphene for power electronics applications for studying the effect of boundary scattering of charge carriers in graphene nanoribbons. The project is sponsored by the Office of Naval Research- global (ONR) - Department of Defense (DOD)- U.S. Navy.
Several recent papers have reported measurements of adhesion energy between graphene and other materials (e.g., Si/SiOx and copper) [1-3]. Like thin films, many experimental methods may be adopted to measure the interfacial properties of graphene, such as the pressurized blister test  and the double-cantilever beam test . The challenges lie in the handling of atomically thin membranes and analysis/interpretation of the data.