The MEMS Handbook Introduction & Fundamentals (2nd Ed) - M Gad el Hak Part 5 ppsx

... of the Navier–Stokes equations, as well as the molecular interaction models of the MD and the DSMC methods. Although it may seem that the molecular simulation methods are more fundamental, they require ... particularly important for simulation of gas flows in MEMS components. If we consider a micromotor or a micro-comb-drive mechanism, gas flow in most of the device can be simul...

Ngày tải lên: 10/08/2014, 02:21

... Taylor & Francis Group, LLC 1 1-2 MEMS: Introduction and Fundamentals attention of MEMS researchers since the early days of MEMS development, and there have been several demonstrations of micromotors ... gradients in the microchannel. Probably the most common cause of this is a mis- match in the height of the fluid level at the reservoirs. Although there may not be...

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... BH) 2 1 ᎏ 2 1 2-3 2 MEMS: Introduction and Fundamentals © 2006 by Taylor & Francis Group, LLC 1 2-6 MEMS: Introduction and Fundamentals FIGURE 12.4 Infrared images of various states as seen in the experiments. ... of film surface deformations is well-correlated with the wavelength of the most amplified linear mode pro- portional to d 2 . Similar conclusions about the...

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... indeterminate set of equations. The continuum model is easier to handle mathematically (and is also more familiar to most fluid dynamicists) than the alternative molecular models. Continuum mod- els ... films fabricated in the shapes of beams and plates by comparing the measured curvatures. These were two-layer composite Mechanical Properties of MEMS Materials 3-9 1 mm FIGURE 3 ....

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... Isotropic Fluid,” J. Fluids Eng. 117, pp. 3 5. Gad- el- Hak, M. (1999) The Fluid Mechanics of Microdevices: The Freeman Scholar Lecture,” J. Fluids Eng. 121, pp. 5 33. Gad- el- Hak, M. (2000) Flow Control: Passive, ... illustrate other ramifications of the large surface-to-volume ratio unique to MEMS and provide a molecular view- point to surface forces. U ᎏ h ϩ 2L o s 4-2...

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... and σ T are the tangential momentum and thermal accommodation coef- ficients respectively. The accommodation coefficients model the momentum and energy exchange of gas mol- ecules impinging on the walls. ... cantilever microbeam made of piezoelectric material. The emphasis may be on modeling the electronic circuit and the motion, and thus a simple model for the motion-induced...

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... Equation Including Thermal Creep Flow,” J. Tribol. 110, p. 253 . Gad- el- Hak, M. (2002) “Flow Physics,” in Handbook of MEMS, 1st ed., M. Gad- el- Hak, ed., CRC Press, Boca Raton. Gallis, M. A., Rader, D.J., ... above Mach numbers of approximately two. Furthermore, the application of the 1 3- or 3 5- moment systems to three-dimensional problems remains computationally proh...

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... MEMS: Introduction and Fundamentals y/y max 0.0 0 .5 1.0 0.0 1.0 2.0 3.0 4.0 5. 0 x/y max FIGURE 8.29 Microchannel geometry and grid. y/y max 1.0 0 .5 0.0 0.0 1.0 2.0 3.0 4.0 5. 0 y/y max 1.0 0 .5 0.0 0.0 1.0 2.0 3.0 ... agree well with the DSMC results. The temperature and Mach number profiles especially show very close agreement with the DSMC 8-3 0 MEMS: Introduction a...

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... along with the theoretical predictions based on the assumed geometry. The right-hand frame shows the same measurements compared with the same model but using slightly modified geometric parameters. ... LLC 1 1-2 0 MEMS: Introduction and Fundamentals them undesirable in a practical MEMS rotor system. The primary difficulty is that, in order to satisfy the requirements of...

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... various examples of their dynamics relevant for MEMS are presented, some of them with reference to the corresponding experimental results. The examples discussed examine isothermal, non-isothermal with ... interfacial jump in the momentum flux, the combination of the fourth and the fifth terms represents the jump in the conductive heat flux at both sides of the interface,...

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