Schematic diagrams of (a) tip-induced deformation, (b) bulge test, and (c) AFM-assisted nanoindentation. (a) Reprinted with permission from C. Gómez-Navarro, M. Burghard and K. Kern, Nano Letters, 2008, 8, 2045–2049.136 Copyright 2008 American Chemical Society. (b) Reprinted with permission from J. S. Bunch, S. S. Verbridge, J. S. Alden, A. M. v. d. Zande, J. M. Parpia, H. G. Craighead and P. L. McEuen, Nano Letters, 2008, 8, 2458–2462,139 Copyright 2008 American Chemical Society. (c) Reproduced from Lee et al., Elastic and frictional properties of graphene, Physica Status Solidi: B, 2009, 246, 2562–2567,140 John Wiley and Sons, © WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.