Effect of environmental conditions and geometric parameters on the squeeze film damping in RF-MEMS switches

Haider, Syed Turab; Saleem, Muhammad Mubasher; Ahmed, Mariam

doi:10.1007/s10470-018-1283-5

Cited by 5 publications

(3 citation statements)

References 27 publications

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“…For each simulation run in the design matrix, the computed values of squeeze number and Reynolds number are in the range of 10 −3 thus air compressibility and inertial damping effects are ignored. A detailed description of modelling of thin film air damping effects in capacitive sensing combs is given by the authors in [40,41].…”

Section: Fem Modelling Of 2-dof Mems Accelerometermentioning

confidence: 99%

A Systematic Design Optimization Approach for Multiphysics MEMS Devices Based on Combined Computer Experiments and Gaussian Process Modelling

Saghir

Saleem

Hamza

et al. 2021

Sensors

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This paper presents a systematic and efficient design approach for the two degree-of-freedom (2-DoF) capacitive microelectromechanical systems (MEMS) accelerometer by using combined design and analysis of computer experiments (DACE) and Gaussian process (GP) modelling. Multiple output responses of the MEMS accelerometer including natural frequency, proof mass displacement, pull-in voltage, capacitance change, and Brownian noise equivalent acceleration (BNEA) are optimized simultaneously with respect to the geometric design parameters, environmental conditions, and microfabrication process constraints. The sampling design space is created using DACE based Latin hypercube sampling (LHS) technique and corresponding output responses are obtained using multiphysics coupled field electro–thermal–structural interaction based finite element method (FEM) simulations. The metamodels for the individual output responses are obtained using statistical GP analysis. The developed metamodels not only allowed to analyze the effect of individual design parameters on an output response, but to also study the interaction of the design parameters. An objective function, considering the performance requirements of the MEMS accelerometer, is defined and simultaneous multi-objective optimization of the output responses, with respect to the design parameters, is carried out by using a combined gradient descent algorithm and desirability function approach. The accuracy of the optimization prediction is validated using FEM simulations. The behavioral model of the final optimized MEMS accelerometer design is integrated with the readout electronics in the simulation environment and voltage sensitivity is obtained. The results show that the combined DACE and GP based design methodology can be an efficient technique for the design space exploration and optimization of multiphysics MEMS devices at the design phase of their development cycle.

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Section: Fem Modelling Of 2-dof Mems Accelerometermentioning

confidence: 99%

A Systematic Design Optimization Approach for Multiphysics MEMS Devices Based on Combined Computer Experiments and Gaussian Process Modelling

Saghir

Saleem

Hamza

et al. 2021

Sensors

Self Cite

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“…For this reason, an important area of research is to increase the quality factor of piezoelectric oscillators [7]. This includes an enhancement of the material-related intrinsic quality factor, as well as the Eng 2022, 3 125 reduction of extrinsic damping effects, being related to environmental ambient pressure and geometrical boundaries [8,9]. In many applications, MEMS oscillators are operated under various ambient conditions, e.g., in a liquid, in a gas atmosphere, or encapsulated under vacuum conditions.…”

Section: Introductionmentioning

confidence: 99%

Generalized Damping Model for MEMS Oscillators from Molecular to Viscous Flow Regime

Zengerle

Ababneh

Seidel

2022

Eng

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In this study, we investigate the damping phenomena acting on piezoelectrically driven MEMS oscillators. Three different geometrical shapes of MEMS oscillators are presented, including cantilevers, bending oscillators, and paddle oscillators. An analytical model for their resonance frequencies is derived. The bending modes of these micro-oscillator structures are characterized regarding their resonance frequency and their quality factor as a function of the ambient pressure in a nitrogen atmosphere as well as the dependence on the distance to a neighboring plate representing a geometrical boundary (e.g., to the package or to the mounting). The investigations cover a pressure range from 10−3 mbar up to 900 mbar and a gap width from 150 µm to 3500 µm. Consequently, a Knudsen number range over six orders of magnitude from 100 to 10−4 is covered. The measurement data are evaluated with a generalized damping model consisting of four parts representing the individual damping mechanisms (intrinsic, molecular, transitional, and viscous). The evaluated parameters are analyzed as a function of the resonance frequency and the gap width. The data reveal an exponential growing saturation behavior, which is determined by two characteristic lengths, being correlated with the viscous and the thermal boundary layer thickness, respectively. This leads to an estimation of the strength and of the range of the damping effect just by calculating the boundary layer thicknesses given by the resonance frequency and the gas properties. From these results, we gain fundamental insights on the viscous and transitional damping mechanisms as well as on the intrinsic losses. In conclusion, a basic concept is provided to reduce the damping of micro-oscillator bending modes and thus increase the quality factor. Additionally, the results are supported by finite element simulations revealing the temperature and pressure distribution within the gap.

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“…Phase images and the quality factor Q are directly related to energy dissipation between the tip and sample [5,6]. Many energy dissipation mechanisms, such as adhesion hysteresis, capillary interactions, air damping, and plastic deformation, have been discussed in previous studies [7][8][9][10][11][12][13]. Increasing the cantilever quality factor Q improves imaging sensitivity and helps to provide high-resolution phase images [14,15].…”

Section: Introductionmentioning

confidence: 99%

Squeeze Film Damping Effect on Different Microcantilever Probes in Tapping Mode Atomic Force Microscope

et al. 2020

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During the operation of tapping mode atomic force microscope (TM-AFM), the gap between the cantilever and sample surface is very small (several nanometers to micrometers). Owing to the small gap distance and high vibration frequency, squeeze film force should be considered in TM-AFM. To explore the mechanism of squeeze film damping in TM-AFM, three theoretical microcantilever simplified models are discussed innovatively herein: tip probe, ball probe, and tipless probe. Experiments and simulations are performed to validate the theoretical models. It is of great significance to improve the image quality of atomic force microscope.

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Effect of environmental conditions and geometric parameters on the squeeze film damping in RF-MEMS switches

Cited by 5 publications

References 27 publications

A Systematic Design Optimization Approach for Multiphysics MEMS Devices Based on Combined Computer Experiments and Gaussian Process Modelling

A Systematic Design Optimization Approach for Multiphysics MEMS Devices Based on Combined Computer Experiments and Gaussian Process Modelling

Generalized Damping Model for MEMS Oscillators from Molecular to Viscous Flow Regime

Squeeze Film Damping Effect on Different Microcantilever Probes in Tapping Mode Atomic Force Microscope

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