Simulation Analysis of Damage Mechanism of Suspended Graphene Film

Suspended graphene has a good application prospect in the field of pressure sensors. However, the current large-scale suspended graphene yield is low. In order to improve the yield of large-scale suspended graphene, it is necessary to analyze the mechanism of film damage. In this paper, COMSOL software was used to perform mechanical modeling and simulation on the graphene suspension release process. Find that the smaller the surface tension of the liquid, the smaller the load on the film during the release of the graphene film. Moreover, the film is prone to break at the formation stage of the triple junction of graphene, liquid, and air. The low fracture strength of large-sized suspended graphene may be attributed to many overlapping grain boundaries and the microscopic flaws. The stress concentration of the thin film caused by the defects of round holes and elliptical holes has been analyzed by simulation. The results show that the stress concentration in the circular pinhole is significantly lower than that obtained from the elliptical pinhole. In addition, stress concentration factor K increases with the smaller b/a value of the elliptical pinhole. The research has important theoretical and practical significance for improving the current graphene suspension release process and improving the yield and quality of large-sized suspended graphene.