Enhancing the Mass Sensitivity of Graphene Nanoresonators Via Nonlinear Oscillations: The Effective Strain Mechanism

TL;DR

This study demonstrates that driving graphene nanoresonators into nonlinear oscillations significantly enhances their mass sensitivity by inducing effective strain, eliminating the need for pre-tensile strain application.

Contribution

The paper introduces a novel mechanism linking nonlinear oscillations to increased mass sensitivity via effective strain in graphene nanoresonators.

Findings

Mass sensitivity triples at 2.5 times initial kinetic energy.

Enhanced sensitivity is due to effective strain from nonlinear oscillations.

Analytic relationship established between actuation energy and effective strain.

Abstract

We perform classical molecular dynamics simulations to investigate the enhancement of the mass sensitivity and resonant frequency of graphene nanomechanical resonators that is achieved by driving them into the nonlinear oscillation regime. The mass sensitivity as measured by the resonant frequency shift is found to triple if the actuation energy is about 2.5 times the initial kinetic energy of the nanoresonator. The mechanism underlying the enhanced mass sensitivity is found to be the effective strain that is induced in the nanoresonator due to the nonlinear oscillations, where we obtain an analytic relationship between the induced effective strain and the actuation energy that is applied to the graphene nanoresonator. An important implication of this work is that there is no need for experimentalists to apply tensile strain to the resonators before actuation in order to enhance the mass sensitivity. Instead, enhanced mass sensitivity can be obtained by the far simpler technique of actuating nonlinear oscillations of an existing graphene nanoresonator.