Noise Immunity of Carbon Nanotube Based Switches

Author(s):  
M. Rasekh ◽  
S. E. Khadem ◽  
M. Tatari

In this paper, two terminals, doubly clamped, nano-switch has been studied. Here the interest of this study is the situation in which the pull-in and pull-out voltages not be same as each other and the pull-in/pull-out trend follows a hysteresis loop. This property could be used to introduce a double threshold switch with greater stability or noise immunity. With only one input threshold, a noisy input voltage signal near that threshold could cause the output to switch rapidly back. The model comprises a clamped-clamped carbon nanotube (CNT) suspended over a graphite ground electrode plate from which a potential difference is imposed. The actuation is based on DC applied voltages and it is assumed that the neutral axis of bending is stretched when the beam is deflected, and also, due to closeness of the substrate and the CNT, the van der Waals interaction forces between CNT and ground plate is considered. The versatile Galerkin’s method is employed to reduce the nonlinear integral-partial-differential equation of motion to a nonlinear ordinary differential equation in time, and then, the reduced equation is solved by direct numerical integration. The pull-in/pull-out phenomena, hysteresis characteristic are studied. The obtained results are compared to Molecular Dynamic (MD) method. Eventually, a nano-switch immune to input noise is proposed which relies on the hysteresis characteristic of the system. The proposed CNT-based nano-switch can operate in nano-scale electronics similar to the well known Schmitt trigger circuit in classical electronics. When the input voltage is higher than a certain pull-in voltage threshold, the output of the switch is in “ON” state; when the input voltage is below the pull-out voltage threshold, the output is in “OFF” state; when the input voltage is between the two threshold values, the output retains in the previous state.

Author(s):  
Sharafat Ali ◽  
Iftikhar Ahmad ◽  
Muhammad Asif Zahoor Raja ◽  
Siraj ul Islam Ahmad ◽  
Muhammad Shoaib

In this research paper, an innovative bio-inspired algorithm based on evolutionary cubic splines method (CSM) has been utilized to estimate the numerical results of nonlinear ordinary differential equation Painlevé-I. The computational mechanism is used to support the proposed technique CSM and optimize the obtained results with global search technique genetic algorithms (GAs) hybridized with sequential quadratic programming (SQP) for quick refinement. Painlevé-I is solved by the proposed technique CSM-GASQP. In this process, variation of splines is implemented for various scenarios. The CSM-GASQP produces an interpolated function that is continuous upto its second derivative. Also, splines proved to be stable than a single polynomial fitted to all points, and reduce wiggles between the tabulated points. This method provides a reliable and excellent procedure for adaptation of unknown coefficients of splines by searching globally exploiting the performance of GA-SQP algorithms. The convergence, exactness and accuracy of the proposed scheme are examined through the statistical analysis for the several independent runs.


2015 ◽  
Vol 82 (11) ◽  
Author(s):  
Riccardo Barsotti

The axisymmetric inflation problem for a wrinkled membrane is solved by means of a simple nonlinear ordinary differential equation. The solution is illustrated in full details. Both the free and constrained cases are addressed, in the limit case where the membrane is fully wrinkled. In the constrained inflation problem, no slippage is allowed between the membrane and the constraining surfaces. It is shown that an actual membrane can in no way reach the fully wrinkled configuration during free inflation, regardless of the membrane's initial configuration and constituent material. The fully wrinkled solution is compared to some finite element results obtained by means of an expressly developed iterative–incremental procedure. When the values of the inflating pressure and length of the meridian lie within a suitable applicability range, the fully wrinkled solution may represent a reasonable approximation of the actual solution. A comparison with some numerical and experimental results available in the literature is illustrated.


2020 ◽  
Vol 4 (1) ◽  
pp. 448-455
Author(s):  
Mulugeta Andualem ◽  
◽  
Atinafu Asfaw ◽  

Nonlinear initial value problems are somewhat difficult to solve analytically as well as numerically related to linear initial value problems as their variety of natures. Because of this, so many scientists still searching for new methods to solve such nonlinear initial value problems. However there are many methods to solve it. In this article we have discussed about the approximate solution of nonlinear first order ordinary differential equation using ZZ decomposition method. This method is a combination of the natural transform method and Adomian decomposition method.


2009 ◽  
Vol 79-82 ◽  
pp. 1205-1208 ◽  
Author(s):  
Cheng Zhang ◽  
Lin Xiang Wang

In the current paper, the hysteretic dynamics of magnetorheological dampers is modeled by a differential model. The differential model is constructed on the basis of a phenomenological phase transition theory. The model is expressed as a second order nonlinear ordinary differential equation with bifurcations embedded in. Due to the differential nature of the model, the hysteretic dynamics of the MR dampers can be linearized and controlled by introducing a feedback linearization strategy.


2020 ◽  
pp. 2150019
Author(s):  
André de Oliveira Gomes ◽  
Michael A. Högele

We establish Freidlin–Wentzell results for a nonlinear ordinary differential equation starting close to the stable state [Formula: see text], say, subject to a perturbation by a stochastic integral which is driven by an [Formula: see text]-small and [Formula: see text]-accelerated Lévy process with exponentially light jumps. For this purpose, we derive a large deviations principle for the stochastically perturbed system using the weak convergence approach developed by Budhiraja, Dupuis, Maroulas and collaborators in recent years. In the sequel, we solve the associated asymptotic first escape problem from the bounded neighborhood of [Formula: see text] in the limit as [Formula: see text] which is also known as the Kramers problem in the literature.


Author(s):  
Mahdi Mojahedi ◽  
Mahdi Moghimi Zand ◽  
Mohammad Taghi Ahmadian

Vibrations of electrostatically-actuated microbeams are investigated. Effects of electrostatic actuation, axial stress and midplane stretching are considered in the model. Galerkin’s decomposition method is utilized to convert the governing nonlinear partial differential equation to a nonlinear ordinary differential equation. Homotopy perturbation method (i.e. a special and simpler case of homotopy analysis method) is utilized to find analytic expressions for natural frequencies of predeformed microbeam. Effects of increasing the voltage, midplane stretching, axial force and higher modes contribution on natural frequency are also studied. The anayltical results are in good agreement with the numerical results in the literature.


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