Utilizing Electron Irradiation to Decrease Friction in Graphene

Graphene, a single layer of carbon atoms, has numerous applications in nanotechnology; however, few studies have explored its frictional properties. This research project examines methods to selectively reduce graphene's friction. Samples were obtained by mechanically exfoliating graphene over holes etched in SiO2, and layer thickness was confirmed through Raman Spectroscopy. Then, the suspended and supported graphene was exposed to electron irradiation under a scanning electron microscope (SEM) at 2.03 x 10^16 e-/cm2 to ensure the first stage of defect formation. Atomic force Microscopy (AFM) was used to capture topographical images and measure surface friction before and after irradiation. The results supported previous studies which showed friction decreased with an increasing number of carbon layers. Suspended samples had less surface friction than supported samples and after electron irradiation, the samples' friction decreased by one-tenth of the original value. The data suggests that electron irradiation could be a method to selectively decrease friction in graphene, having potential applications for graphene or carbon-based microelectronics and micromechanical devices.