[...]... 2-8 MEMS: Applications the spring constant in the lateral axis of sensitivity only increases linearly The aspect ratio, or ratio of the height to width of the spring, impacts the relative difference in stiffness both in- and out-of-plane Since the spring constant in the lateral axis of sensitivity is defined by the chosen geometry of the device, simply increasing its geometrical length or reducing the. .. by Taylor & Francis Group, LLC 2-6 MEMS: Applications Electrode A Poly A Support Rim FIGURE 2.3 Scanning electron micrograph of an ultra-high-resolution X-lateral accelerometer with micro-g resolution (Photo courtesy of K Najafi, University of Michigan.) d 2x F ϭ ma ϭ ᎏ dt 2 (2.5) The accelerometer design needs to precisely control the displacement of the seismic mass The structure should be sufficiently... device Again, the thickness of the sense fingers improves the stiffness of a beam design and increases nominal capacitance per finger The size and stiffness of the mass can also be affected by technological constraints such as the nature of the sacrificial release etch Since the proof-mass is typically by far the largest feature in an inertial sensor, the release of the proof-mass from the substrate... is the elastic spring constant tensor (N/m) and x is the spatial displacement of the mass with respect to the reference frame generated by the inertial load: F ϭ ϪKx (2.6) In the ideal case, the proof-mass displacement is well controlled and in one axis only The ratio of the proofmass to spring constant defines the sensitivity of the system to inertial loads The spring constant associated with the. .. included in the three books constituting the second edition of The MEMS Handbook The 16 chapters in MEMS: Introduction and Fundamentals provide background and physical considerations, the 14 chapters in MEMS: Design and Fabrication discuss the design and fabrication of microdevices, and the 15 chapters in MEMS: Applications review some of the applications of microsensors and microactuators There are... closely spaced parallel plates oscillate in a direction parallel to each other, and this damping generated by a gas film is referred to as shear damping Under the small motion assumption in one axis, the flow-induced force is linearly proportional to the displacement and velocity of the moving plates A single-axis dynamic model of an accelerometer is shown in Equation 2.8 The coefficient of the velocity... methodology converts the mechanical displacement to an electrical output Linear devices are classified either as in-plane (often denoted X-axis or X-lateral) and out-of-plane (or Z-axis) The choice of axis is primarily driven by the application Front airbag systems require lateral sensing, whereas side and satellite airbag sensors are often mounted vertically and call for Z-axis sensing While these two types... order to improve the yield of manufacturing 2.4.1 Converting Acceleration to Force: The Seismic Mass The application of an inertial load exerts a force on the proof-mass, which is translated into a displacement by the elastic spring The simple force equation for a static load is shown in Equation 2.5 — where m is the proof mass (kg) and a is the static or steady-state inertial acceleration (m/s2) —... LLC Yitshak Zohar .1 2-1 Haecheon Choi 1 4-1 The farther backward you can look, the farther forward you are likely to see (Sir Winston Leonard Spencer Churchill, 1874–1965) Janus, Roman god of gates, doorways and all beginnings, gazing both forward and backward As for the future, your task is not to foresee, but to enable it (Antoine-Marie-Roger de Saint-Exupéry, 1900–1944, in Citadelle [The Wisdom... NanoTechnologyResources.htmlϾ The three-book MEMS set covers several aspects of microelectromechanical systems, or more broadly, the art and science of electromechanical miniaturization MEMS design, fabrication, and application as well as the physical modeling of their materials, transport phenomena, and operations are all discussed Chapters on the electrical, structural, fluidic, transport and control aspects of MEMS are . lift enhancement and mixing augmentation in wall-bounded flows; and for developing a novel viscous pump suited for microelectromechanical systems (MEMS) applications. Gad- el- Hak s work on Reynolds num- ber. Francis Group, the academic division of T&F Informa plc. Boca Raton London New York Edited by Mohamed Gad- el- Hak The MEMS Handbook Second Edition MEMS Applications © 2006 by Taylor & Francis. Handbook, Second Edition MEMS: Introduction and Fundamentals MEMS: Design and Fabrication MEMS: Applications Mohamed Gad- el- Hak Nonlinear Analysis of Structures M. Sathyamoorthy Practical Inverse