University of North Texas 
Abstract
Recent advances in graphene and other two-dimensional (2D) material synthesis and
characterization have led to their use in emerging technologies, including flexible
electronics. However, a major challenge is electrical contact stability, especially
under mechanical straining or dynamic loading, which can be important for 2D material
use in microelectromechanical systems. In this letter, we investigate the stability
of dynamic electrical contacts at a graphene/metal interface using atomic force microscopy
(AFM), under static conditions with variable normal loads and under sliding conditions
with variable speeds. Our results demonstrate that contact resistance depends on the
nature of the graphene support, specifically whether the graphene is free-standing
or supported by a substrate, as well as on the contact load and sliding velocity.
The results of the dynamic AFM experiments are corroborated by simulations, which
show that the presence of a stiff substrate, increased load, and reduced sliding velocity
lead to a more stable low-resistance contact.
J.Lee, X. Hu, A. Voevodin, A. Martini, D. Berman*: “Effect of substrate support on dynamic graphene/metal electrical contacts”, Micromachines 9 (4), 169 (2018).