Ji-Beom Yoo

The mechanical properties of nanometer-thick graphite film (NGF) and graphene were characterized using a bulge test. Young’s modulus, fracture stress, residual strain and stress of the NGF were measured. The NGF was synthesized on a Ni/SiO 2 /Si substrate using a chemical vapor deposition system. Large-area freestanding NGF was prepared via camphor transfer. Young’s modulus, fracture stress and fracture strain of the NGF were 106 GPa, 462 MPa, and 0.3%, respectively, confirming that the bulge test is a very useful technique for evaluating the mechanical properties of NGF. A bulge test was performed to evaluate the mechanical properties of graphene with a free-standing poly (bisphenol A carbonate) (PC)/graphene layer. Large-area freestanding PC/2D material layers were prepared by peeling-off and stamping. The PC layer was used as the supporting layer in this study. Young’s modulus of graphene was calculated from Young’s modulus of the PC/2D material layers and PC layers using the rule of mixtures. Young’s modulus of the graphene was 260 GPa. The results of this study confirm the efficacy of the bulge test for determining the mechanical properties of nanometer-thick films and 2D materials, including graphene.