Effect of Pressure on Fluid Damping in MEMS Torsional Resonators with Flow Ranging from Continuum to Molecular Regime

Pandey, Ashok Kumar; Pratap, Rudra; Chau, Fook Siong

doi:10.1007/s11340-007-9076-2

Cited by 45 publications

(45 citation statements)

References 27 publications

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“…A detailed understanding of viscous damping, squeezed-film damping, and acoustic radiation has been obtained for numerous devices including plates, membranes, beams, torsional resonators, and hollow resonators containing internal microfluidic channels. The dependence of damping on material properties, fluidic properties, geometry, size, confinement, mode, frequency, pressure, and temperature has been captured well by models (see, for example, [14,16,[40][41][42]64,[68][69][70]). …”

Section: Review Of Dampingmentioning

confidence: 96%

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Design strategies for controlling damping in micromechanical and nanomechanical resonators

2014

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Damping is a critical design parameter for miniaturized mechanical resonators usedin microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS),optomechanical systems, and atomic force microscopy for a large and diverse set ofapplications ranging from sensing, timing, and signal processing to precisionmeasurements for fundamental studies of materials science and quantum mechanics.This paper presents an overview of recent advances in damping from the viewpointof device design. The primary goal is to collect and organize methods, tools, andtechniques for the rational and effective control of linear damping in miniaturizedmechanical resonators. After reviewing some fundamental links between dynamicsand dissipation for systems with small linear damping, we explore the space ofdesign and operating parameters for micromechanical and nanomechanicalresonators; classify the mechanisms of dissipation into fluid–structure interactions(viscous damping, squeezed-film damping, and acoustic radiation), boundarydamping (stress-wave radiation, microsliding, and viscoelasticity), and materialdamping (thermoelastic damping, dissipation mediated by phonons and electrons,and internal friction due to crystallographic defects); discuss strategies for minimizingeach source using a combination of models for dissipation and measurements of material properties; and formulate design principles for low-loss micromechanical and nanomechanical resonators

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Section: Review Of Dampingmentioning

confidence: 96%

“…When the pressure is reduced further, fluidic damping becomes negligible at a critical value which is a function of the size, shape, and mode of the resonator. The critical pressure has been measured to range from 0.1 Pa to 10 3 Pa for miniaturized mechanical resonators [14,29,[40][41][42].…”

Section: Fluid-structure Interactions (Fsi)mentioning

confidence: 99%

Design strategies for controlling damping in micromechanical and nanomechanical resonators

2014

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“…Here z, , ̈ are the displacement, velocity, and acceleration of the system respectively [12]. An flexural mode resonator has been analytically developed and numerically validated by FEM models in COMSOL Multiphysics in order to optimize the Q sensitivity without affecting the device capacitance [12], [13].The pressure sensor design has an effective mass of 0.4 µg with an optimal geometry of 140 µm × 140 µm × 8 µm having 6 × 6 perforations along the row and column of the plate, respectively, to achieve maximum Q while presenting an acceptable capacitance variation to the electronics [14].…”

Section: Device Design and Fabricationmentioning

confidence: 99%

“…where KB is the Boltzmann constant (1.38e-23 J/K), d is the mean molecular diameter of the molecule (3.7x10 -10 m), is the mean free path of the molecule, T and P are the operating temperature and pressure respectively while h0 is the characteristic device length, which is z0 = 2.5 µm, in our case [14]. In Equation (2), Kn has been used to characterize both pressure and temperature, which in turn has characterized the device performance in terms of Q, discussed in the following sub-sections.…”

Section: B Device Characterization Under Environmentalmentioning

confidence: 99%

Characterization of CMOS-MEMS Resonant Pressure Sensors

2017

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“…All vibratory structures have mechanical resonance characteristics that depend on the ambient pressure. That is, resonance characteristics can be used to estimate the ambient pressure [3][4][5]. Eq.…”

Section: Introductionmentioning

confidence: 99%

Wafer-Level Packaged MEMS Resonators with a Highly Vacuum-Sensitive Quality Factor

Kang¹,

Moon²,

Son³

et al. 2014

JSTS:Journal of Semiconductor Technology and Science

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Abstract-Mechanical stress and the vacuum level are the two main factors dominating the quality factor of a resonator operated in the vacuum range 1 mTorr to 10 Torr. This means that if the quality factor of a resonator is very insensitive to the mechanical stress in the vacuum range, it is sensitive to mainly the ambient vacuum level. In this paper, a wafer-level packaged MEMS resonator with a highly vacuumsensitive quality factor is presented. The proposed device is characterized by a package with out-of-plane symmetry and a suspending structure with only a single anchor. Out-of-plane symmetry helps prevent deformation of the packaged device due to thermal mismatch, and a single-clamped structure facilitates constraint-free displacement. As a result, the proposed device is very insensitive to mechanical stress and is sensitive to mainly the ambient vacuum level. The average quality factors of the devices packaged under pressures of 50, 100, and 200 mTorr were 4987, 3415, and 2127, respectively. The results demonstrated the high controllability of the quality factor by vacuum adjustment. The mechanical robustness of the quality factor was confirmed by comparing the quality factors before and after hightemperature storage. Furthermore, through more than 50 days of monitoring, the stability of the quality factor was also certified.

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Effect of Pressure on Fluid Damping in MEMS Torsional Resonators with Flow Ranging from Continuum to Molecular Regime

Cited by 45 publications

References 27 publications

Design strategies for controlling damping in micromechanical and nanomechanical resonators

Design strategies for controlling damping in micromechanical and nanomechanical resonators

Characterization of CMOS-MEMS Resonant Pressure Sensors

Wafer-Level Packaged MEMS Resonators with a Highly Vacuum-Sensitive Quality Factor

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