Local strain mapping of GO nanosheets under in situ TEM tensile testing

Abstract Local strain mapping of 2D materials at nanoscale under continuous deformation can enable a variety of studies on 2D materials including but not limited to more accurate characterization of physical properties, heterogeneity characterization of functionalized 2D materials, and strain engineering of 2D materials. Here, using graphene oxide (GO) as a representative material, we report a technique that achieves local strain mapping of 2D materials at nanoscale through gold nanoparticle decoration over GO under in situ TEM tensile testing and imaging. Our results reveal that GO at different uniaxial tensile strain levels exhibits a heterogeneous local strain distribution. Using this technique, the permanent deformation of GO was also quantified to be ∼1% on average. The technique can be readily applied to the strain mapping of other 2D materials.