Invited Paper MN+GR-ThM1
Graphene Mechanics, Tribology, and NEMS Resonators

Thursday, November 12, 2009, 8:00 am, Room A8

This talk will describe our work toward fundamental understanding of the mechanical and and tribological properties of graphene, and its application in nano-electromechanical devices (NEMS). We have used nanoindentation to measure the elastic stiffness and ultimate strength of single graphene sheets¹. These measurements show that graphene is the strongest material ever measured, with an ultimate strength of 130 GPa at an ultimate strain of over 25%. As such, it is the first material whose mechanical properties can be probed deep into the nonlinear elastic regime. We have also measured the frictional behavior of graphene and other related two-dimensional materials. These materials all show an unexpected strong dependence of the frictional force the number of atomic layers, with thinner samples demonstrating larger friction. Finally, we have demonstrated electronic readout of graphene nanomechanical resonators. These devices show highly tunable mechanical resonances in the range 20-300 MHz, with large output signal compared to other NEMS of comparable size. The quality factor of these resonators increases from ~100 at room temperature to ~10,000 at low temperature. The measured sensitivity of these resonators to applied mass shows their promise as multifunctional sensors.

[1] Changgu Lee, Xiaoding Wei, Jeffrey Kysar, J. Hone, “Measured elastic properties and ultimate strength of monolayer graphene,” Science 321, 385 (2008)