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Announcement(s)
What are MEMS? And, why should we learn how to model and design them?
MEMS (Micro-Electro-Mechanical Systems) is an acronym that describes the rapidly growing field of multi-disciplinary research on micro-scale systems. It is also known as MST(Microsystems Technology).
MEMS represents integrated systems of small size where the feature sizes are generally of micron dimensions, but sometimes even larger extending up to millimeters. More important than this "size" characterization, the unique feature of MEMS is the extent to which actuation, sensing, control, manipulation, and computation are integrated in the same system. The notion of integration is also inherent in the way MEMS are manufactured. The same applies to modeling and design. And, that is why special attention is given to the subject we will be studying in this course.
MEMS devices are not only smaller, but also cheaper and more functional with fast response times than their micro counterparts. This is the principal reason for pursuing MEMS from commercial viewpoint. An array of individually controlled micro-mirrors used in a projection display, the ink-jet printers, accelerometers that sense a crash condition and activate airbags in cars, pressure sensors, and optical NxN cross-connects are some of the commercially successful applications of MEMS. There are also "lab-on-a-chip" systems where micro-fluidics plays a large role. Power MEMS, where power is generated from microsystems, is also attracting increasing attention. There are also "chemical-plants-in-a-box" the offing. Many other applications and concepts are envisioned and billion dollar markets are predicted--some have come true and some, many hope, will do so in the future.
With its early origins in mid-to-late 1960's and accelerated development since late eighties, MEMS field has sufficiently matured now. The "gee-whiz" "show-and-tell" era of "cool" miniaturized devices has almost ended; large and small MEMS industries are seriously competing in the commerical market. Efforts are underway to optimize performance and cost and improve the reliability of MEMS. Microfabrication is expensive and time-consuming, which makes it uneconomical to rely upon "build-and-test" approach. Therefore, the issues of simulating them and designing them have become very important. There are now a large number of companies whose mission is developing software for modeling and designing MEMS.
Is modeling and design of MEMS different from that of traditional macro ststems? The answer to this is no and yes. "No" beacuse there is virtually no new physics or chemistry in most MEMS devices. And therefore, the governing equations are the same as we know them at the macro scale. "Yes" because there are scaling effects that change coefficients in these equations radically and bring about interesting consequences. And then there is integration. How do you simulate and design a device that tightly couples effects of several domains, sometimes all in a single structure? By "domains", we here refer to physical and chemical phenomena such as elastic, electrostatic, thermal, magnatic, dynamics, optical, fluidic, etc. Thus, we often need to solve equationas that govern two or more domains simulataneously. Now, think about the system-level issues. How do you design a system that integrates components of several types such as elastic structures, electronic circuits, fluidic elements, optical units, etc. -- all on the same platform? We will discuss these issues in this course.
While our focus is on modeling and design, of necessity, we will also learn about microfabrication and the operating principles of various MEMS devices. So, you get a bird's eye view of the MEMS field as a bonus.
Sharpen your pencils to write and work things down on paper. Sharpen also your finger tips as you will be writing fair amount of code to numerically solve the equations you write on paper.