Manipulation of graphene's dynamic ripples by local harmonic out-of-plane excitation

With use of carefully designed molecular dynamics simulations, we demonstrate tuning of dynamic ripples in free standing, thermally fluctuating graphene by applying a local out-of-plane sinusoidal excitation. The local dynamic morphology can be controlled via varying external modulation and the boundary conditions. We fully account for the discrete atomistic structure of graphene, as well as natural energy dissipation due in part to its remarkably high thermal conductivity. In addition to stable dynamic rippling patterns, we observed an unexpected flattening of graphene well below the thermal limit. Our results provide insight into the dynamic response of atomically thin layers to an external time-varying excitation in the presence of realistic thermal fluctuations and energy loss. This suggests intriguing possibilities for modulating the electrical and optical properties of atomically thin membranes via local dynamic morphology control.