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This paper deals with the investigation of nonlinear static pull-in instability of smart Nano-switches regarding the new size-dependent phenomenon, known as flexoelectricity, together with the surface effects. It is noteworthy that the coupling effect of the flexoelectricity and surface elasticity on nonlinear static pull-in instability of electrostatically-actuated Nano-switches has not been studied before. Euler-Bernoulli beam assumptions in conjunction with the von-Karman nonlinearity are considered to formulate the problem. The Nano-switch is subjected to electrostatic actuation force with fringing field effect as well as Casimir force. Refined constitutive relations for piezoelectric materials capturing the flexoelectric effects are taken into consideration for mathematical modeling. Additionally, a surface elasticity approach is employed to reach an accurate model for the system. Considering the imposed electric boundary conditions, Gauss’s equation is solved to acquire the electric potential distribution along with the thickness of the Nano-switch. Thereafter, Hamilton’s principle is hired to derive the coupled nonlinear governing equations of the system. Utilizing the differential quadrature method (DQM), the nonlinear ordinary differential equations are transformed into a system of nonlinear algebraic equations. Consequently, Newton-Raphson method is exploited as a numerical method to solve the obtained algebraic equations which leads to the pull-in voltage. Investigating the maximum displacement of the Nano-switch in response to the applied electrostatic force, the effects of various involved parameters such as flexoelectricity and surface elasticity on pull-in instability are explored in detail. Furthermore, the size-dependent behavior of the pull-in instability against the flexoelectric, surface effects and applied piezoelectric voltage is analyzed. Totally, it is revealed that the flexoelectricity may exhibit a substantial influence on the pull-in behavior of smart Nano-switches, especially for some cases with small thicknesses. Therefore, this effect should be taken into account to reach an accurate, reliable and optimized design for Nano-switches.

Capacitive micromachined ultrasonic transducers (CMUTs) are dominant in generating and receiving acoustic signals. CMUT transmission efficiency solely depends upon the membrane material utilized. This work presents the structural examination of receiving and transmitting characteristics of CMUT with divergent membrane materials, namely Silicon (Si), Silicon Nitride ( Si 3 N 4 {\mathrm{Si}_{3}}{\text{N}_{4}} ), Indium Phosphide (InP), Zinc Oxide (ZnO), and Polysilicon (Poly-Si). The analysis includes the membrane deflection, pull-in voltage, output pressure, resonant frequency and capacitance modification with variable DC voltage. It has been found that InP gives the pull-in voltage comparable to Si in the receiving mode and have more transduction efficiency in transmitting mode. Effect of dimensions of CMUT on pull-in voltage and resonant frequency are also discussed. The major contribution lies in the analytical and estimation study of CMUT for appropriate membrane material selection meant for transmission and reception in the field of pressure sensing application.

Purpose This paper aims to present a nonclassical circular plate model subjected to hydrostatic pressure and electrostatic actuations by considering the modified couple stress theory and the surface elasticity theory. The pull-in phenomenon and nonlinear behavior of circular nanoplate are investigated. Design/methodology/approach The hybrid differential transformation method (DTM) and finite difference method (FDM) are used to approach the model. The DTM was first applied to the equation with respect to the time, and then the FDM was applied with respect to the radius. Findings The numerical results were in agreement with the numerical data in the previous literature. The effects of the length scale parameters, surface parameters, thermal stress, residual stress, hydrostatic pressure and electrostatic actuations of the nonclassical circular plate on the pull-in instability are investigated. The parametric study demonstrated that the pull-in behavior of the circular nanoplate was size dependent. Originality/value In this study, the results provide a suitable method in a nonclassical circular plate model. The length scale parameter had an obvious effect on the nonlinear behavior of the circular nanoplate.

The modelling and simulation of nanoelectromechanical (NEM) switch is indispensable to get optimum device dimensions. The present work deals with the design and simulation of hinge structure-based ...

This paper presents the design a capacitive shunt type RF-MEMS switch with high isolation, high switching speed and low actuation voltage for Ka-band applications. The proposed RF-MEMS switch has chosen different structures to reduce the actuation voltage. This paper investigates various analysis such as Electromechanical and RF characteristics of the proposed switch. The beam material taken as the gold and the dielectric is taken as Si3N4 with ℰr as 7.5 and the pull-in voltage of proposed switch obtained as 3.37 V. The proposed different RF-MEMS switches have been analyzed over the range of 26.5–40 GHz frequency. The clamped-clamped structure type RF MEMS Switch is having high isolation as − 46.37 dB at 40 GHz. The perfection of RF losses makes these switches as a good choice for a high frequency of K-band.

Recent Advancements in the wireless communication systems utilizes miniaturized devices based on Micro – Electro – Mechanical System technology for present and future 5G wireless applications. Now a days, RF devices are utilizing the frequencies upto 30 GHz and a huge traffic in signal propagation occurs which leads to the slow data rate. In other hand, there is a huge spectrum available in the millimetre wave frequency range of 30 – 300 GHz. The millimetre wave spectrum is attractive for development of smart systems based on 5G technology. In this paper, A low pull – in voltage capacitive type RF MEMS switch is proposed to operate at the frequencies above 30 GHz. The switch is proposed with new iterative meandering technique where span length of each section in meanders differs and dependable with first section. A low pull – in voltage of 1.8V is achieved with large capacitance ratio of 63. The switch exhibits low insertion loss of -0.24 dB at 41 GHz and possess high isolation of -46.7 dB at 38 GHz. The design is validated by comparing the theoretical and simulated results and the switch can be efficiently utilized for millimeterwave applications.

In this paper, we have designed an optimal design of microelectromechanical (MEMS) resonator. The paper explains the idea of suitable design, modeling and optimization of the MEMS RF resonator. The resonator has been designed to achieve a high quality factor and optimum pull in voltage and keeping the dimension as small as possible. The design approach uses the Dragonfly algorithm for minimizing the pull in voltage. The resonator is basically a perforated structure incorporating circular holes.

The novel model of the coupled beam-type electrodes with elastic roots, subjected to the AC and DC voltages is constructed. The exact critical pull-in voltage of the two coupled elastically...

In this paper, pull in voltage in closed form model is derived from the capacitance generated in RF MEMS switches during ON and OFF conditions. The proposed model contains the ligament efficiency term and can be applicable for all perforated RF MEMS switches. The proposed model is validated by computing error percentage between simulated and modelled values. The proposed switch with the non-uniform meander with dimensions tb=0.5 μm, td=0.1 μm, airgap=2 μm, Wb=120 μm, silicon nitride as a dielectric and gold as a beam material shows a very low error percentage of 3.9% and chosen as the best dimensions for proposed model of step structure RF MEMS switch.

Pull-in analysis of an electrostatically actuated nonuniform micro-resonator under large elastic deflection has been investigated with a focus on qualitative analysis to understand the essence of nonuniform cross-section on the determination of pull-in voltage. Here, a microcantilever beam with nonuniform cross-section has been adopted to develop a mathematical model considering the important features such as structural nonlinearities, nonlinear electrostatic distribution, and linear viscous effect. The individual effect of each design variables on the diagnosis of the critical voltage and corresponding critical deflection due to pull-in has been graphically depicted. The results in the static condition have been verified with the findings obtained via COMSOL multi-physics software. Present result indicates that a nonuniform microbeam configuration strengthens the structural stability by switching the pull-in voltage up to a higher value. Similarly, stable pull-in deflection within the restriction of pull-in instability has been also augmented. In addition, it has been shown that the nonuniformity within the beam structure is highly sensitive to the nonlinear effects. Hence, outputs provide a useful insight of pull-in behavior and enable an understanding of safe and smooth operating range of microelectromechanical system devices.

In this paper, a novel, computationally efficient and simple closed-form expression has been derived to accurately calculate the pull-in voltage value of fixed-fixed micro-actuator. At first, microelectromechanical systems actuators with various physical parameters have been simulated by a software that employs the finite element method, the pull-in voltage expression has been derived by using the artificial bee colony optimization algorithm together with the simulation data. Since the formula is derived from the simulation data, it implicitly contains the fringing field, mid-plane stretching and size effects. In order to verify the accuracy and robustness, the predictions of closed-form formula proposed in this work have been compared with those of the theoretical ones through the simulation and experimental studies previously presented in the literature. The key advantage of the presented method is delivering a satisfying estimation of the pull-in voltage with a simple and easy way.

Relays are electromechanical switches which are normally used to control high power electrical machineries. It is very important part for a control a single circuit or multiple circuits either with a low power signal or high-power signals. In this paper Carbon nanotube Relay has been used with trench of gold as electrode material and characteristics of carbon nanotube relay such as histogram of outer diameters, histogram of inner diameters, histogram of lengths, pull in voltage vs outer diameter, pull back voltage vs outer diameter, pull in voltage vs length, pull back voltage vs length, pullback voltage vs pull in voltage with various samples of 10, 100, 1000 and 10,000 and its values are simulated and its values are noted., {"references":["Donatello A, Adrian IM (2010) Nano-Electro-Mechanical Switches Based on Carbon Nanotubes Arrays.","Kaul A, Epp L, Wong E (2008) Carbon nanotube mechanical relays for electronics.","Sansiri Tanachutiwat, Wei wang (2015) Carbon Nanotube Relay"]}

This paper presents the pull-in voltage study of Bimorph electrostatic actuated Cantilever beam. Electrostatic actuation requires very high actuation Voltage to pull the cantilever. Bimorph Cantilever beam could be used to reduce the actuation Voltage. COMSOL Multiphysics Electromechanics interface is used to simulate the Pull-in Voltage. We Compare the Pull-in Voltage of different Bimorph Cantilever beam Materials. The Analytical and Simulation result shows that the pull-in voltage of Aluminum and Gold Bimorph Cantilever is 4.05V and is less compared to other Bimorph Cantilever beam materials simulated.

One of the easiest and the most appropriate solution for fabricating MEMS switch is Electrostatic actuation. However, it requires large parallel plates which can take a large surface on the substrate wafer and thus an expensive fabrication cost. In this paper, an improved electrostatic MEMS switch is presented. The proposed design is carried out so that it minimizes the dimensions of the MEMS device. Simulation results are also done by COMSOL based on the proposed design.

A 2D finite element analysis of capacitive micromachined ultrasonic transducer (CMUT) is proposed taking into account radiation in air and water. Different CMUT element geometries circular, square and hexagonal have been considered for FEM simulations. FEM simulation software COMSOL is employed to determine the structural deflections caused by electrostatic forces. Since the structural deformation alters the electrostatic field, a coupled-field simulation is required wherein the electrostatic mesh is continuously updated to coincide with the deflection of the structure. In this paper the deflection profile, resonance frequency, material parameters and collapse mode characteristics are being compared with device in air and under water. The CMUT is an electromechanical system, therefore, the physics of electrical and structural mechanics is coupled to describe its dynamics. Maximum frequency of operation is obtained by deriving the time evolution of the device for several frequencies.

We designed a one-mask process for all-molybdenum-based laterally actuated nanoelectromechanical switches. The damascene-like process is designed to ensure a smooth, high-aspect ratio, and metal-to-metal mechanical contact. Based on the statistical study of 800 devices, very high process yield can be achieved for fixed–fixed beam devices by selecting suitable device dimensions, i.e., the beam length versus beam width ratio should be 1.5. Typical failure modes are also discussed. [2014-0391]

In this paper, Cantilever based RF MEMS switches are designed and simulated for applications in reconfigurable antennas. Due to the low cost and ease of fabrication Cantilever based RF MEMS switch is preferred. The CoventorWare software (FEM) is used for the simulation of the proposed RF MEMS switch. The pull in voltage is calculated using the formulas and analyzed using MATLAB. Based on the analysis of the dependence of these parameters on the geometry of the cantilever, it is designed and simulated using CoventorWare software. Using this software the optimization of the design of the cantilever switch is performed for minimum pull in voltage. The pull in voltage for the proposed design is obtained as 34 V.

Electrostatically-actuated Micro device have been used widely in a variety of integrated sensors and actuators. Electrostatically-actuated micro devices with a gap of several micrometers or less between the electrodes have shown failure problems by electrostatic adhesion. To improve this adhesion phenomenon, micro devices of varying lengths and widths in electrodes were fabricated, and an alumina coating was then deposited using atomic layer deposition technology. The effects of improving adhesion phenomenon were compared by measuring the pull-in voltage before and after the coating process. The pull-in voltage increased with increasing length of the upper electrode after the coating. An increase in the electrode area results in an increase in the pull-in voltage after coating. The alumina coating method applied to improve the adhesion on an electrostatically-actuated micro device was observed as an effective method.

The study of temperature effects on pull-in voltage-based inclinometers is reported here. A 75 μ°-resolution MEMS inclinometer that uses pull-in voltages as the transduction mechanism is tested at different temperatures and inclinations. The microstructures used have differential actuation electrodes enabling the measurement of two pull-in voltages that change with acceleration. Both the difference between left and right pull-in voltages (used to measure the inclination) and the nominal pull-in voltage (in absence of inclination) are retrieved and used for thermal compensation. Experimental results demonstrate a compensated inclinometer with high-resolution and with thermal stability better than 0.01%FS.

The Ansys simulate software is utilized to analyze pull-in voltages and stresses of the fixed end of micro- cantilever beam with different thicknesses respectively. Based on the analysis of the electrostatic force at the pull-in voltage, the stress of fixed end of micro-beam and the maximum deflection are obtained. The relationship between the stress of fixed end and thickness is established. The results show that the mutation thickness of the stress and the pull-in voltage are at and respectively , it is consistent with the intrinsic size of the polycrystalline copper micro-beam.

This paper is about, the design and analysis of shunt capacitive RF MEMS switch with less actuation voltage, low insertion losses and high isolation losses. The switch design is incorporated the Electrostatics MEMS actuation technique with vertically deforming bridge. In terms of actuation voltage the switch performance is improved by choosing step type actuation structure with holes. The switch Radio Frequency (RF) performance is analysed over the frequency range from 0.6 to 40 GHz. The major achievements in this work are actuation voltage is reduced to 4.2 V for 0.9 μm displacement, the return loss is below −16 dB, the insertion loss is below −0.44 dB, and the isolation loss is −20 dB. The dielectric material used between the membrane and the CPW line is Aluminum Nitride (AlN) with dielectric constant 9.5. The substrate material used for the CPW transmission line is quartz with dielectric constant 3.9. The bridge is designed with meanders, step structure by using gold material with thickness 0.5 μm. The switch upstate capacitance is capacitance ratio of the shunt capacitive switch is 65.22.

The effect of a sacrificial layer residue on a cantilever beam in the nano-electro-mechanical nonvolatile memory is investigated for the optimization of reliability characteristics. Different from previous research, pull in voltage model of nano-electro-mechanical nonvolatile memory used triangular residue layer which is considered by real wet etching process. Modified pull in voltage model was investigated with triangular shape sacrificial layer residue. Keyword Nano Electro Mechanical Nonvolatile Memory, pull in voltage

In this paper an analytical solution for size-dependent response of cantilever micro-beams is presented. Using the modified couple stress theory, the small scale effects are accounted for. Employing the Modified Variational Iteration Method, efficient and accurate analytical expressions for the deflection of the micro-beam are presented. Very good agreement is observed between the present work results and available experimental data. This study may be helpful to characterize the size-dependent mechanical properties of MEMS. Consequently, the proposed analytical solution can be used as an efficient tool for studying the effects of the material or geometrical parameters on small scale devices consisting of micro-beams for their design and optimization which requires a large number of simulations.

Parallel-plate capacitor whose plates both fixed to elastic supports is presented and analyzed in this paper, and its cantilevers model is analyzed to study the parameter dependence of pull-in voltage. The whole process of voltage calculation is based on material mechanics theories and analytical methods, and the results are verified by simulation of MEMS software, which is mainly aiming at the effects of plate dimensions on pull-in voltage. It is concluded that the longer are the supporting beams, the smaller are the effects of plate’s parameters on voltage, besides, the effect extent of longitudinal length of plate is little larger than that of transverse length.

A new varying section cantilever beam type RF MEMS switch has been proposed. The main advantage of this switch is that it is inherently stiction free and therefore enhances design flexibility. An analytical model developed using unit load approach for the spring constant of the proposed switch has been presented and it has been shown that the spring constant and therefore the pull in voltage (Vpi) can be considerably reduced with the proposed switch. Simulation studies conducted on two groups of devices clearly demonstrate that the pull in voltage can be reduced by 26% with ten sections. Comparision of the pull in voltage obtained in the simulation studies for devices with the theoretically estimated Vpi shows that the spring constant model presented in this paper accurately estimates the spring constant. The results of analytical studies also demonstrate that the new proposed cantilever beam can considerably reduce the pull in voltage.

Let Ω ⊂ R n be a C 2 bounded domain and χ > 0 be a constant. We will prove the existence of constants λ N ≥ λ N ∗ ≥ λ ∗ ( 1 + χ ∫ Ω d x 1 − w ∗ ) 2 for the nonlocal MEMS equation − Δ v = λ / ( 1 − v ) 2 ( 1 + χ ∫ Ω 1 / ( 1 − v ) d x ) 2 in Ω , v = 0 on ∂ Ω , such that a solution exists for any 0 ≤ λ λ N ∗ and no solution exists for any λ > λ N where λ ∗ is the pull-in voltage and w ∗ is the limit of the minimal solution of − Δ v = λ / ( 1 − v ) 2 in Ω with v = 0 on ∂ Ω as λ ↗ λ ∗ . Moreover λ N ∞ if Ω is a strictly convex smooth bounded domain. We will prove the local existence and uniqueness of the solution of the parabolic nonlocal MEMS equation u t = Δ u + λ / ( 1 − u ) 2 ( 1 + χ ∫ Ω 1 / ( 1 − u ) d x ) 2 in Ω × ( 0 , ∞ ) , u = 0 on ∂ Ω × ( 0 , ∞ ) , u ( x , 0 ) = u 0 in Ω . We prove the existence of a unique global solution and the asymptotic behaviour of the global solution of the parabolic nonlocal MEMS equation under various boundedness conditions on λ . We also obtain the quenching behaviour of the solution of the parabolic nonlocal MEMS equation when λ is large.

Pull-in characteristics of microcantilevers subjected to both residual stress gradients and electrostatic fringing are investigated by extending the previous JMEMS work by Ou using an energy approach. The analysis results agree with those performed by finite-element simulation very well. Finally, a semi-analytical engineering formula is also presented for MEMS design engineers.

The stepped microbeams are typical low stiffness structures widely used in MEMS devices. Approximated solutions of the natural frequency and the pull-in voltage of stepped microbeams, including clamped-free (CF) and clamped–clamped (CC) boundary conditions are developed, and the unique pull-in behavior of the stepped microbeams is investigated. The stepped microbeam is viewed as a beam with a rectangular electrode pad at its tip for CF beam and at its center for CC beam. The motion equations are deduced based on the Euler–Bernoulli beam and the modified couple stress theory. The natural frequency and the pull-in voltage are extracted with a one-degree-of-freedom model. The present model correctness is validated by comparing with the finite element results, and the effect of the length ratio of the electrode pad to the beam and the width ratio of the beam to the electrode pad are discussed. The results show that both the natural frequency and the pull-in voltage monotonously increase with the increase of the width ratio, and first decrease and then increase with the increase of the length ratio. The minimum value of them does not appear at the same time, but is determined by the width ratio. The results can be used to design and improve the performance of MEMS devices.

A trial solution for bending deflection of a multilayered micro-bridge subject to a voltage induced load is presented. The relation between the applied voltage and the displacements of the micro-bridge in the pull-in state is analyzed by energy method. Furthermore, two analytical expressions about normalized displacement and pull-in voltage are carried out. It’s proved that the value of normalized displacement is not influenced by residual stress if axial and shear deformation is ignored. Finally, the theoretical results are compared with that of FEM, and they show good agreement.

This paper derives an approximate analytical solution to the pull-in voltage of a micro bridge with elastic boundaries. The analytical model considers the elastic boundary effect, fringing field capacitance, residual stresses and the distributed flexibility of the bridge. The accuracy of the present approximate analytical solution is verified by comparison with the simulation results of commercial FEM packages and other published closed-form solutions as well as experimental measured data. The deviation of the present approximate analytical solution is within 5% for a wide beam and a narrow beam in a small deflection regime. The present approximate analytical solution has explicit physical meaning and is highly accurate for device design.

In order to provide the pull-in voltage, angle and height of two-degree-of-freedom (two-DOF) torsional microactuators, closed-form expressions for the pull-in parameters have been successfully obtained from numerical analysis with new formulation of the microactuator. Force and moment balance equations governing the behaviors of the microactuator are obtained as functions of dimensionless force and moment. Thereafter, a mode equation to easily solve the angle and height of the 2-DOF torsional microactuator is derived. A set of the mode equation and the force balance equation is numerically solved for the height and angle of the two-DOF torsional microactuator. For design convenience, closed-form expressions for the pull-in voltage, angle and height are given as functions of the applied voltage and geometry. The theoretical height and angle are in good agreement with experimental data within an error of 2.6% and 4.3%, respectively. As such, the closed-form expressions as well as the developed theory can be used for design and analysis of two-DOF torsional microactuators.

This paper presents experimental and theoretical investigation of a new concept of switches (triggers) that are actuated at or beyond a specific level of mechanical shock or acceleration. The principle of operation of the switches is based on dynamic pull-in instability induced by the combined interaction between electrostatic and mechanical shock forces. These switches can be tuned to be activated at various shock and acceleration thresholds by adjusting the dc voltage bias. Two commercial off-the-shelf capacitive accelerometers operating in air are tested under mechanical shock and electrostatic loading. A single-degree-of-freedom model accounting for squeeze-film damping, electrostatic forces and mechanical shock is utilized for the theoretical investigation. Good agreement is found between simulation results and experimental data. Our results indicate that designing these new switches to respond quasi-statically to mechanical shock makes them robust against variations in shock shape and duration. More importantly, quasi-static operation makes the switches insensitive to variations in damping conditions. This is promising for lowering the cost of packaging for these switches since they can operate in atmospheric pressure with no hermetic sealing or costly packaging required.

A statistical study has been done for all-metal-based laterally actuated nanoelectromechanical switch. 500 devices with 50 different dimensions have been characterized in terms of pull-in voltage and fabrication yield. An analytical solution to predict the pull-in voltage with only 2% deviation compared to finite element modeling is developed. Switches of robust designs show 100% fabrication yield and repeatable switching behavior.

The study includes Micro-Electro-Mechanical System (MEMS) electrostatic actuator using SIMULINK software tool considering equivalent mathematical model. This paper deals with the equation of motion, electrostatic force for the analysis of pull in voltage and displacement of an electrostatic cantilever with respect to the changes in applied force (voltage). Considering these equation, we have developed SIMULINK model to analyze pull in voltage, and displacement for the various applied input voltage. Keywords: MEMS, electrostatic cantilever, SIMULINK Cite this Article: Huddar S, Sheeparamatti BG, Hallikeri G, et al. Analysis of MEMS electrostatic actuator using SIMULINK software tool. Journal of Instrumentation Technology & Innovations. 2015; 5(1): 32–35p.

This paper derives a high precision analytical solution to determine the pull-in voltages of a micro curled beam subjected to electrostatic loads. The analytical model considers the fringing fields between the micro curled beam and the ground plane as well as the initial curling induced by the stress gradient. Furthermore, the electromechanical coupling effects are also involved in the present analytical model. Then the analytical solution of pull-in voltage is obtained by the energy method. By comparing with the other published analytical models as well as the experimentally measured data, the accuracy of the present analytical solution is verified to be more accurate than the other published works. The present analytical solution can determine the pull-in voltage with a maximum deviation of 1% from the experimentally measured results as the ratio of the beam length to the width is greater than 5.