Calculation of pull-in voltages for carbon-nanotube-based nanoelectromechanical switches

Abstract

We study the pull-in voltage characteristics of several nanotube electromechanical switches, such as double-wall carbon nanotubes suspended over a graphitic ground electrode. We propose parametrized continuum models for three coupled energy domains: the elastostatic energy domain, the electrostatic energy domain and the van der Waals energy domain. We compare the accuracy of the continuum models with atomistic simulations. Numerical simulations based on continuum models closely match the experimental data reported for carbon-nanotube-based nanotweezers. An analytical expression, based on a lumped model, is derived to compute the pull-in voltage of cantilever and fixed-fixed switches. We investigate the significance of van der Waals interactions in the design of nanoelectromechanical switches.

Modeling a Suspended Nanotube Oscillator

“…Since their discovery in 1991 [6], nanotubes have found many applications in device technology due to their small size, robust structure and superior elastic properties [7,8,9,10]. Many of these applications involve the use of nanotubes as mechanical oscillators, making theoretical understanding of the vibrational properties of nanotubes in various geometries of current interest [4,11]. Recent experiments [12] have studied the behavior of the transverse vibrations of a suspended nanotube clamped at both ends, under the action of a downward force, as sketched in Figure 1.…”

Regularization of chaos by noise in electrically driven nanowire systems

“…Let h be the vertical distance between the clamped ends of the nanowire and the surface of the substrate, d = 2r be the cross-sectional diameter of the wire, and V (t) be the external voltage applied to the wire. Under the condition h d so that the oscillation amplitude is much smaller than that for the onset of the pull-in effect [8,9], the electrical force per unit length is given by [18] …”

“…Their small size, extremely low power consumption, and ultrafast operational speed are among the virtues that have been exploited for significant applications ranging from single-electron spin detection [1] and Zeptogram scale mass sensing [2] to rf communications [3], semiconductor superlattice [4,5], and many others [6][7][8][9][10][11][12][13][14]. From the perspective of basic science, NEM systems represent a novel class of high-dimensional nonlinear dynamical systems.…”

“…To see why NEM systems are fundamentally nonlinear and thus chaos can arise, we take as an example an electrostatically driven nanowire [1,2,8,9,[12][13][14][20][21][22], a paradigm for investigating nonlinear behaviors in nanoscale systems [15,18,19]. When the nanowire moves, the amount of stretching can be expressed as an integral of nonlinear functions of the displacements (see Sec.…”

Contact angle influence on the pull-in voltage of microswitches in the presence of capillary and quantum vacuum effects

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] A typical microswitch is constructed from two conducting electrodes, where one electrode is usually able to move but still remains suspended by a mechanical spring. By applying a voltage difference between the two electrodes, the mobile electrode moves towards the ground electrode due to the electrostatic force.…”