Molecular dynamics modeling and simulations to understand gate-tunable graphene-nanoribbon-resonator

et al. 2021

Nanomaterials

In consideration of the presented optical-thermally excited resonant mass detection scheme, molecular dynamics calculations are performed to investigate the thermal actuation and resonant mass sensing mechanism. The simulation results indicate that an extremely high temperature exists in a 6% central area of the graphene sheet exposed to the exciting laser. Therefore, constraining the laser driving power and enlarging the laser spot radius are essential to weaken the overheating in the middle of the graphene sheet, thus avoiding being burned through. Moreover, molecular dynamics calculations demonstrate a mass sensitivity of 214 kHz/zg for the graphene resonator with a pre-stress of 1 GPa. However, the adsorbed mass would degrade the resonant quality factor from 236 to 193. In comparison, the sensitivity and quality factor could rise by 1.3 and 4 times, respectively, for the graphene sheet with a pre-stress of 5 GPa, thus revealing the availability of enlarging pre-stress for better mass sensing performance.

Section: Models and Methodsmentioning

confidence: 63%

Optical-Thermally Excited Graphene Resonant Mass Detection: A Molecular Dynamics Analysis

Xing

et al. 2021

Nanomaterials

“…With molecular dynamics, Kwon et al studied a nano-scale graphene-nanoribbonresonator in 2012, finding that the resonant frequency of graphene is greatly affected by driving force and axial strain, and that the tunable range of resonant frequency decreases exponentially with the increase of axial strain or driving force, as shown in Figure 6 [68,69]. Because most graphene bending deflection is in the elastic region of graphene, the function between resonant frequency and tension can be explained by classical continuum mechanics.…”

Section: Molecular Dynamicsmentioning

confidence: 99%

Research Progress of Graphene Nano-Electromechanical Resonant Sensors—A Review

Zhao

et al. 2022

Micromachines

Graphene nano-electromechanical resonant sensors have wide application in areas such as seawater desalination, new energy, biotechnology, and aerospace due to their small size, light weight, and high sensitivity and resolution. This review first introduces the physical and chemical properties of graphene and the research progress of four preparation processes of graphene. Next, the principle prototype of graphene resonators is analyzed, and three main methods for analyzing the vibration characteristics of a graphene resonant sheet are described: molecular structural mechanics, non-local elastic theory and molecular dynamics. Then, this paper reviews research on graphene resonator preparation, discussing the working mechanism and research status of the development of graphene resonant mass sensors, pressure sensors and inertial sensors. Finally, the difficulties in developing graphene nano-electromechanical resonant sensors are outlined and the future trend of these sensors is described.

“…In addition, Oshidari et al reported a graphene resonator by attaching SU-8 proof mass onto graphene, and studied the effect of temperature on the resonance frequency and quality factor variations of the resonator [13]. Recently, Kown et al further investigated the mechanical response of graphene harmonic oscillator under nano-indentation by molecular dynamics method, which indicates that the resonance behaviors of graphene resonator can be tuned by nano-pressure and initial displacement [14,15]. Although currently, graphene mechanical resonators mainly adopt electrical excitation to actuate the sensitive elements [11,12,13,14,15,16], this type of excitation mode is generally limited to high measurement accuracy and better repeatability.…”

Section: Introductionmentioning

confidence: 99%

Opto-thermally Excited Fabry-Perot Resonance Frequency Behaviors of Clamped Circular Graphene Membrane

Shi

et al. 2019

Nanomaterials

An opto-thermally excited optical fiber Fabry-Perot (F-P) resonant probe with suspended clamped circular graphene diaphragm is presented in this paper. Then, the dependence of resonance frequency behaviors of graphene diaphragm upon opto-mechanical factors including membrane properties, laser excitation parameters and film boundary conditions are investigated via COMSOL Multiphysics simulation. The results show that the radius and thickness of membrane will linearly affect the optical fiber light-induced temperature distribution, thus resulting in rapidly decreasing resonance frequency changes with the radius-to-thickness ratio. Moreover, the prestress can be regulated in the range of 108 Pa to 109 Pa by altering the environmental temperature with a scale factor of 14.2 MPa/K. It is important to note that the availability of F-P resonant probe with a defective clamped circular graphene membrane can be improved notably by fabricating the defected circular membrane to a double-end clamped beam, which gives a broader perspective to characterize the resonance performance of opto-thermally excited F-P resonators.