Research Of Graphene Mechanical Property With A Nanorobotic System

Graphene,which is composed of a single layer of carbon atoms, is a new type of two-dimensional carbon nanomaterials. It attracts wide attention because of its excellent physical, chemical and mechanical properties. Besides it has extensive research value and application prospect. The special structure of graphene determines its unique properties. The study of graphene’s mechanical properties has extremely important significance to promote the development of graphene, such as the adhesion or friction properties.In this paper, the adhesion property between the material of probe(Au) and the surface of different samples is studied with a nanorobotics system. The work of adhesion between the probe and surface of each sample is obtained through analyzing the adhesion property between them by JKR model of elastic contact. The difference of friction properties between graphene and silica is compared, and the friction imaging of graphene and silica is studied under different conditions. Finally, the nanoindentation experiment is achieved in the suspended graphene membrane, and its Young’s modulus is acquired by nonlinear elastic model fitting. The main research contents are as follows:(1) Preparation of graphene sample. The liquid-phase exfoliation by ultrasonic and micromechanical cleavage are used for the preparation of graphene sample. The detection technology of Raman spectroscopy is used to analyze the graphene samples. The analysis results show that the quality of graphene sample obtained by micromechanical cleavage is good, which basically meets the requirements of grachene properties in the research level.(2) The test and analysis of graphene adhesion. The corresponding test program of adhesion based on F-D curve multiparametric scanning model is developed. It’s applied to study the adhesion property between the surface of different samples and the material of probe(Au) in the different relative humidity. Then, the work of adhesion between them is calculated by the JKR model of elastic contact.(3) The test and analysis of graphene friction and the research of friction imaging. The difference of friction between graphene and silica is studied by the friction loops method. The corresponding program of friction imaging based on this difference is developed. The friction imaging of the different layers of graphene is implemented in silica or graphene substrate.(4) The Young’s modulus of graphene is obtained by nanoindentation experiment. A 10-by-10-mm array of circular wells(diameters 4.2 μm, depth 400 nm) was patterned onto a Si substrate with a 300-nm Si O2 epilayer. Graphene are then mechanically deposited onto the substrate. The nanoindentation experiment is carried out in single suspended graphene films. Finally, the Young’s modulus and film pretension of graphene is obtained by nonlinear elastic model fitting.The test method of adhesion property mentioned in this paper can quickly and accurately obtain and quantify the adhesion between graphene and a variety of other materials, which could accelerate the pace of the application of these two-dimensional materials.