Ultra-High Frequency Nano-mechanical Resonator with Graphene/Graphene Oxide Doubly Clamped Beam

The remarkable properties of graphene have renewed interest in ultra-high frequency nano-electromechanical systems (NEMS) with extraordinary mechanical and electronic attributes. However, the resonant frequency of graphene NEMS is still under 300MHz at room temperature. To further increase the resonator frequency, this paper presents an ultra-high frequency nano-mechanical resonator by using graphene/graphene oxide (G/GO) doubly clamped beam.The results show that the resonator frequency of G/GO nanomechanical resonator can reach up to 350.2MHz

Frequency Tuning of Graphene Nanoelectromechanical Resonators via Electrostatic Gating

In this article, we report on a comprehensive modeling study of frequency tuning of graphene resonant nanoelectromechanical systems (NEMS) via electrostatic coupling forces induced by controlling the voltage of a capacitive gate. The model applies to both doubly clamped graphene membranes and circumference-clamped circular drumhead device structures. Frequency tuning of these devices can be predicted by considering both capacitive softening and elastic stiffening. It is shown that the built-in strain in the device strongly dictates the frequency tuning behavior and tuning range. We also find that doubly clamped graphene resonators can have a wider frequency tuning range, while circular drumhead devices have higher initial resonance frequency with same device characteristic parameters. Further, the parametric study in this work clearly shows that a smaller built-in strain, smaller depth of air gap or cavity, and larger device size or characteristic length (e.g., length for doubly clamped devices, and diameter for circular drumheads) help achieve a wider range of electrostatic frequency tunability. This study builds a solid foundation that can offer important device fabrication and design guidelines for achieving radio frequency components (e.g., voltage controlled oscillators and filters) with the desired frequencies and tuning ranges