Nonlocal Timoshenko shear beam model for multilayer curved graphene nano-switches

Abstract

Graphene sheets are the basis of nano-electromechanical switches, which offer a unique insight into the world of quantum mechanics. In this paper, we proposed a new size-dependent multi-beam shear model for investigating the pull-in instability of multilayer graphene/substrate nano-switches within the context of the Timoshenko beam theory. As the graphene/substrate bemas bent toward the graphene layer due to the thermomechanical mismatch, the impact of curvature is considered in the proposed model. Also, the impact of the Casimir attraction is incorporated in the developed model by taking into account the limited conductivity of interacting surfaces. The scale dependency of the materials is considered in the framework of the nonlocal elasticity. To simulate the nano-switch and explore the pull-in instability, a finite element procedure is developed. The proposed approach is verified by comparing the pull-in voltage to published data. Finally, the role of influential parameters, including size dependency, length, initial gap, curvature, and the number of graphene layers on instability voltage of nano-switch, are investigated.

Theoretical prediction of proteins network-induced nonlocal response in molecules-resonator biosensor with hydrogen bonds including van der waals interactions

“…Based on the present formulation, we investigate in this section the vibration frequency shift. Calculations are made by changing the thickness surface ratio and the distribution density of adatoms and proteins for a rectangular microbeam with a value of b = 1nm as width and various values of thickness 2h and length L. The selected nanomaterial is the Au(100) single-crystalline with mass density of ρ = 19.3 g cm -3 , modulus of elasticity of E = 78.6 GPa, Poisson ratio of ν = 0.42, constant of surface elastic of S = 0.329 eV Å −2 andasurface stress of τ 0 = 1.4 N m −1 [40] to investigate its effect on the induced shift including the effect of the parameter of small scale of value e o a = 0.2L [29,33,40]. The energetic parameters in relationship with different interatomic interactions during localization of Hydrogen (H) and Oxygen (O) adatoms are shown in table 1.Notes that the dimensional parameter Θ = η/η m is defined as the relative distribution density taken in account η m = 1/c 2 to model the importance of distribution density of adatoms.…”

“…In contrast to the standard elasticity theory, the nonlocal theory of material elasticity [29,32] is a scale-dependent approach that accounts for the influence of small scales. Since researchers have adopted this theory, numerous investigations have widely confirmed its effectiveness in computing the induced behavioral shift due to the effect of small sizes for components with nanometric dimensions [33]. Presently, analyses have applied the nonlocal approach to various types of materials [34,35] to determine both linear [36] and nonlinear [33] vibrations for uniform or nonuniform [37,38] cross-sections.…”

“…Since researchers have adopted this theory, numerous investigations have widely confirmed its effectiveness in computing the induced behavioral shift due to the effect of small sizes for components with nanometric dimensions [33]. Presently, analyses have applied the nonlocal approach to various types of materials [34,35] to determine both linear [36] and nonlinear [33] vibrations for uniform or nonuniform [37,38] cross-sections. Ghorbanpour Arani et al [39] concluded that the shift in local behavior with respect to nonlocal behavior increases according to a parametric function in relation to the wave number.…”

Influence of temperature on the pull-in characteristics of nano-switches considering surface effect

“…In recent years, the rapid development of micro-nano scale manufacturing technology has led to the increasingly wide application of micro-nano electromechanical systems. Nano-switch [1,2] is the basic component for designing nanoelectromechanical systems. The nano-switch structure is usually composed of two parallel conductive electrodes, one of which is fixed and simulated grounding, and the other is movable.…”