Systematic Studies of Surface Friction on Graphene via Lateral Force Measurements

HONG WEI LAI^1*, GUO BO HONG¹, WEI SHIUAN TSENG¹

¹光電系統所, 陽明交通大學, 台南, Taiwan

* Presenter:HONG WEI LAI, email:will30241@gmail.com

In this study, high quality single layer graphene was synthesized via plasma enhanced chemical vapor deposition (PECVD) with relatively low temperature along with no need of active heating. After synthesis, the as-grown single-layer graphene was then transferred onto SiO2 substrates by bubbling transfer method to study surface friction by Atomic Force Microscopy. Here, four variables (normal force, substrate types, lateral spring constant of tips, and curvature of tips) are modified accordingly to investigate the friction behavior on both PECVD-synthesized graphene and commercial single-layer graphene surface. Systematic studies indicated the lateral spring constant (KL) governed the surface friction while tip curvature played a minor role. In addition, when tips with similar KL were used, curvature of tip stood out, demonstrating a clear trend that lower friction values were observed while using tip with larger curvature. Friction coefficients from both commercial and our home-made graphene surfaces approached superlubricity threshold (0.01), suggesting excellent graphene quality as well as potential of future applications for lubricant.

Keywords: PECVD, surface friction, single layer graphene, single layer graphene