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Interfacial mechanics between graphene and substrate such as friction and adhesion plays a critical role in the morphology and functionality of graphene-based devices. Here I will present the interface sliding and buckling of monolayer graphene on a stretchable substrate. The nonlinear mechanical response of monolayer graphene on polyethylene terephthalate (PET) is characterized using in-situ Raman spectroscopy and atomic force microscopy. Although interfacial stress transfer leads to tension in graphene as the PET substrate is stretched, retraction of the substrate during unloading imposes compression in the graphene. Two interfacial failure mechanisms, shear sliding under tension and buckling under compression, are identified. Using a nonlinear shear-lag model, the interfacial shear strength is found to range between 0.46 and 0.69 MPa. The critical strain for onset of interfacial sliding is ~0.3%, whereas the maximum strain that can be transferred to graphene ranges from 1.2% to 1.6% depending on the interfacial shear strength and graphene size. Beyond a critical compressive strain of ~‑0.7%, buckling ridges are observed after unloading. In addition, I will present adhesion measurement using atomic force microscope. REFERENCE [1] Jiang, T., Huang, R., Zhu, Y. Interfacial sliding and buckling of monolayer graphene on a stretchable substrate. Adv. Func. Mat. 2014, 24, 396‑402.

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Interfacial mechanics of graphene

Interfacial mechanics between graphene and substrate such as friction and adhesion plays a critical role in the morphology and functionality of graphene-based devices. Here I will present the interface sliding and buckling of monolayer graphene on a stretchable substrate. The nonlinear mechanical response of monolayer graphene on polyethylene terephthalate (PET) is characterized using in-situ Raman spectroscopy and atomic force microscopy. Although interfacial stress transfer leads to tension in graphene as the PET substrate is stretched, retraction of the substrate during unloading imposes compression in the graphene. Two interfacial failure mechanisms, shear sliding under tension and buckling under compression, are identified. Using a nonlinear shear-lag model, the interfacial shear strength is found to range between 0.46 and 0.69 MPa. The critical strain for onset of interfacial sliding is ~0.3%, whereas the maximum strain that can be transferred to graphene ranges from 1.2% to 1.6% depending on the interfacial shear strength and graphene size. Beyond a critical compressive strain of ~‑0.7%, buckling ridges are observed after unloading. In addition, I will present adhesion measurement using atomic force microscope. REFERENCE [1] Jiang, T., Huang, R., Zhu, Y. Interfacial sliding and buckling of monolayer graphene on a stretchable substrate. Adv. Func. Mat. 2014, 24, 396‑402.