2008/07/17 by Changgu Lee, Xiaoding Wei, Jeffrey W. Kysar +1 · 7 citations
Materials Science · Physics and Astronomy · #Graphene research and applications #Force Microscopy Techniques and Applications #Carbon Nanotubes in Composites
paper · doi:10.1126/science.1157996
openalex publication_date 2008/07/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.