▎ 摘　　要

Graphene resonators are fabricated using a polymer-free, direct transfer method onto metal reinforced holey carbon grids. The resonators are distinguished by the absence of organic residues and excellent crystallinity. The normal mode frequencies are measured using a Fabry-Perot technique; resonance curves indicate highly linear behaviour but very little built-in strain, which is consistent with device geometry examined by atomic force microscopy. We conclude that the oscillators' restoring force is due instead to graphene's intrinsic bending rigidity; our measurements indicate a value of approximately 1.0 eV, consistent with previous theoretical and experimental work. ((c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)