Nanomechanical Z Shape Folding and Unfolding of Graphene and Direct Measurement of the Mechanical Strength of Carbon Nanotube-Metal Interfac

Graphene, which is a type of ultra-thin two dimensional nanomaterial with excellent mechanical and electrical properties, and is considered as an ideal building block for origami kirigami. Constructed originally flat graphene sheet through folding into different sculptures is not only an artwork but also a promising approach for a variety of engineering applications, such as energy storage, biosensors and 3D optics. In order to optimize these applications, the bending stiffness and folding behavior should be fully understood. In this part of the study, the bending stiffness and interlayer shear modulus were investigated through examining its self- folding conformation on flat substrate by using atomic force microscopy (AFM) combined with nonlinear mechanics modeling. Secondly, an experimental study of folding and unfolding graphene on flat substrate by using atomic force microscopy probe was performed to reveal that the out-of-plane buckling delamination of graphene occurs in its early-stage folding process and the reversibility of graphene folding.;Carbon nanotubes, a strong and light weight 1 D tubular structure material, are considered as promising reinforcements for metal matrix composite (MMC) due to its excellent mechanical and physical properties. However, the mechanical performance of carbon nanotube reinforced metal composites is still lack of understanding regarding the CNT-metal interface is the essential challenge to be tackled. Understand the interfacial stress transfer between carbon nanotubes (CNTs) and metal matrices is of great importance to the development of CNT reinforced-metal nanocomposites. In this study, we report a single tube pull-out testing scheme based on in situ nanomechanical characterization techniques inside a scanning electron microscopic (SEM) and quantitatively characterize the interfacial strength between individual double-walled carbon nanotubes (DWCNTs) and aluminum.