scholarly journals Analysis of the Thermoelastic Damping Effect in Electrostatically Actuated MEMS Resonators

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1124
Author(s):  
Florina Serdean ◽  
Marius Pustan ◽  
Cristian Dudescu ◽  
Corina Birleanu ◽  
Mihai Serdean

An important aspect that must be considered when designing micro-electro-mechanical systems (MEMS) for all domains, including robotics, is the thermoelastic damping which occurs when the MEMS material is subjected to cyclic stress. This paper is focused on a model for the thermoelastic damping developed based on the generalized thermoelastic theory with the non-Fourier thermal conduction equation. The model was implemented in MATLAB and several simulations were performed. The theoretical results show a decrease in the deflection amplitude with the increase in time. The deflection amplitude decrease was validated by the experimental investigations, consisting of measuring the loss in amplitude and velocity of oscillations as a function of time. Moreover, this paper also presents the influence of the geometric dimensions on the mentioned decrease, as well as on the initial and final values of the amplitude for several polysilicon resonators investigated in this paper.

Author(s):  
Dumitru I. Caruntu ◽  
Christian Reyes

This paper deals with the voltage-amplitude response (or voltage response) of superharmonic resonance of second order of MEMS resonator sensors under electrostatic actuation. The system consists of a MEMS flexible cantilever above a parallel ground plate. The AC frequency of actuation is near one fourth the natural frequency. The voltage response of the superharmonic resonance of second order of the structure is investigated using the Reduced Order Model (ROM) method. Effects of voltage and damping voltage response are reported.


Author(s):  
Timothy Moulton ◽  
G. K. Ananthasuresh

Abstract There exists a need to stabilize the electrostatic actuation commonly used in Micro-Electro-Mechanical Systems (MEMS). Most electrostatically actuated MEMS devices act as variable capacitors with varying gap between the charged conductors. Electrostatic force in these devices is a nonlinear attractive force between the conductors resulting in a complex dynamic system. These systems are stable for only a small portion of the initial gap. In this paper a design method is presented for electrostatic micro-mirrors with improved stability. Controllable, stable electrostatic actuation can be achieved through surface contact between the two conductors. Once in contact with the surface, the compliance of the structure is used to stabilize the electrostatic actuation over a long range of motion. Beam based variable angle mirrors were designed and fabricated using the Multi-User MEMS Process at MCNC technology center. The design methods for stable electrostatic actuation were tested on these mirrors. Some characteristics are noted and their implementation into future designs is discussed.


2019 ◽  
Vol 11 (10) ◽  
pp. 1950098
Author(s):  
Mohammad Fathalilou ◽  
Pegah Rezaei-Abajelou ◽  
Afsoon Vefaghi ◽  
Ghader Rezazadeh

Due to the interesting properties such as light weight and high deformation ability, dielectric elastomer (DE) resonators can be good alternatives for conventional silicon resonant beams used in micro-electro-mechanical systems (MEMS). This paper proposes a modeling in which a pre-stretched clamped-clamped DE-based microbeam oscillating above the ground substrate is subjected to an external electrostatic pressure. Using a DE-based beam affects the total rigidity of the system, which may lead to an anticipated saddle-node or pitchfork bifurcation. Hence, the present study tries to analyze the effects of DE properties on changing the stability regime of DE-based microbeams under electrostatic actuation. The stability of the system has been investigated using an eigen-value form of the problem. The effects of DE properties including pre-stress, relative permittivity and voltage value across the electrodes on pull-in or divergence instability as well as the frequency response of the system have been investigated. Moreover, the critical values of the DE voltage as a booster of instability occurrence have been obtained in either the presence or absence of the direct current (DC) voltage. It has been found that the pre-stress and appropriate DE permittivity can provide a needed magnitude of the DE actuating voltage to alter the resonance frequency and stability positions of the structure.


2018 ◽  
Vol 26 (23) ◽  
pp. 1911-1919 ◽  
Author(s):  
Niloofar Ghiathinejad ◽  
Mahdi Moghimi Zand ◽  
Mojtaba Haghighi-Yazdi ◽  
Roozbeh Dargazany

Author(s):  
Dumitru I. Caruntu ◽  
Kyle N. Taylor

This paper deals with the nonlinear response of an electrostatically actuated cantilever beam system composed of two micro beam resonators near natural frequency. The mathematical model of the system is obtained using Lagrange equations. The equations of motion are nondimensionalized and then the method of multiple scales is used to find steady state solutions. Both AC and DC actuation voltages of the first beam are considered, while the influence on the system of DC on the second beam is explored. Graphical representations of the influence of the detuning parameters are provided for a typical micro beam system structure.


2019 ◽  
Vol 19 (07) ◽  
pp. 1950072 ◽  
Author(s):  
S. K. Lai ◽  
X. Yang ◽  
C. Wang ◽  
W. J. Liu

This work aims to construct accurate and simple lower-order analytical approximation solutions for the free and forced vibration of electrostatically actuated micro-electro-mechanical system (MEMS) resonators, in which geometrical and material nonlinearities are induced by the mid-plane stretching, dynamic pull-in characteristics, electrostatic forces and other intrinsic properties. Due to the complexity of nonlinear MEMS systems, the quest of exact closed-form solutions for these problems is hardly obtained for system design and analysis, in particular for harmonically forced nonlinear systems. To examine the simplicity and effectiveness of the present analytical solutions, two illustrative cases are taken into consideration. First, the free vibration of a doubly clamped microbeam suspended on an electrode due to a suddenly applied DC voltage is considered. Based on the Euler–Bernoulli beam theory and the von Karman type nonlinear kinematics, the dynamic motion of the microbeam is further discretized by the Galerkin method to an autonomous system with general nonlinearity, which can be solved analytically by using the Newton harmonic balance method. In addition to large-amplitude free vibration, the primary resonance response of a doubly clamped microbeam driven by two symmetric electrodes is also investigated, in which the microbeam is actuated by a bias DC voltage and a harmonic AC voltage. Following the same decomposition approach, the governing equation of a harmonically forced beam model can be transformed to a nonautonomous system with odd nonlinearity only. Then, lower-order analytical approximation solutions are derived to analyze the steady-state resonance response of such a problem under a combination of various DC and AC voltage effects. Finally, the analytical approximation results of both cases are validated, and they are in good agreement with those obtained by the standard Runge–Kutta method.


2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Michael Raulli ◽  
Kurt Maute

The increased use of micro-electro-mechanical systems (MEMS) as key components for actuation and sensing purposes in novel devices and systems emphasizes the need for optimal design methods. Stochastic variations in manufacturing and operational conditions must be considered in order to meet performance goals. This study proposes a reliability based design optimization methodology for the design of geometrically complex electrostatically actuated MEMS. The first order reliability method is used for reliability analysis of fully-coupled electrostatic-mechanical problems. A general methodology for predicting the instability phenomenon of pull-in and incorporating it into an automatic optimization process is proposed and verified with analytical and experimental results. The potential of this methodology is illustrated with the design of an analog micromirror.


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