Imaging mechanical vibrations in suspended graphene sheets.

摘要: We carried out measurements on nanoelectromechanical systems based multilayer graphene sheets suspended over trenches in silicon oxide. The motion of the was electrostatically driven at resonance using applied radio frequency voltages. mechanical vibrations were detected a novel form scanning probe microscopy, which allowed identification and spatial imaging shape eigenmodes. In as many half resonators measured, we observed new class exotic nanoscale vibration eigenmodes not predicted by elastic beam theory, where amplitude is maximum free edges. By modeling with finite element method, these edge are shown to be result nonuniform stress remarkably large magnitudes (up 1.5 GPa). This stress, arises from way prepared pressing or rubbing bulk graphite against another surface, should taken into account future studies electronic properties graphene.