Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout

TL;DR

This paper demonstrates the fabrication and electrical characterization of monolayer graphene nanomechanical resonators, revealing their response to mass and temperature changes, and highlighting their potential for high-sensitivity sensing applications.

Contribution

It provides a comprehensive analysis of monolayer graphene resonators' performance, including their resonance behavior, mass sensitivity, and thermal properties, establishing foundational knowledge for future NEMS applications.

Findings

Resonance frequencies in the MHz range.

Frequency shifts with temperature reveal negative thermal expansion.

Quality factor reaches ~10,000 at 5 K.

Abstract

The enormous stiffness and low density of graphene make it an ideal material for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and electrical readout of monolayer graphene resonators, and test their response to changes in mass and temperature. The devices show resonances in the MHz range. The strong dependence of the resonant frequency on applied gate voltage can be fit to a membrane model, which yields the mass density and built-in strain. Upon removal and addition of mass, we observe changes in both the density and the strain, indicating that adsorbates impart tension to the graphene. Upon cooling, the frequency increases; the shift rate can be used to measure the unusual negative thermal expansion coefficient of graphene. The quality factor increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing many of the basic attributes of monolayer graphene resonators, these studies lay the groundwork for applications, including high-sensitivity mass detectors.