Mechanical testing of graphene presents a significant challenge due concerns regarding sample preparation as well as the extremely high force resolution needed to measure deformation in a single atomic monolayer. Nevertheless, suitable characterization techniques are highly sought after for this novel material due to its extraordinary mechanical and electrical properties.
When deposited on a substrate, nanoindentation can be used to study the adhesion properties of monolayer, bilayer, or multilayer graphene. In an environmental SEM, such studies can be performed at varying humidity levels, which can have a strong influence on the adhesion between tip and sample. Suspended graphene drums can also be probed in order to estimate Young’s Modulus. Nanoscratch testing can also be performed to measure tribological properties, determine friction coefficient, or study failure modes under a ramping load. For free standing graphene specimens, the Push-to-Pull device can be used to study mechanical or electromechanical properties of graphene in tension.