Design Rules
Design Rules
[EDITOR’S NOTE: The following article was written by one of A.P.’s auxiliary staff scientists. Dr. Fausz holds a Ph.D. in Aerospace Engineering from Georgia Tech and serves as liaison to the NASA Marshall Space Flight Center. (All images in Dr. Fausz’ article are Courtesy of Sandia National Laboratories, SUMMiTTM Technologies, www.mems.sandia.gov.)]
One of the most fascinating areas of modern engineering research is the development of what has become known as MicroElectroMechanical Systems, or MEMS. Imagine a closed-cycle steam engine no bigger than a pinhead that operates on a single drop of water (e.g., Frechette, et al., 2003, pp. 335-344), or mirror mechanisms for micro-optical systems with structures that can be obscured by a single dust mite (McWhorter, 2001; McWhorter, 2006).
These devices are so miniscule that their operational performance has to be verified through a microscope. MEMS devices are used to actuate airbags in automobiles, precisely control optics in digital projectors and video cameras, and perform a variety of other functions (see “SAMPLES Program,” 2005; “MEMS Technology,” 2006). Yet, we have barely scratched the surface of possible applications for MEMS.
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Spider mite on mirror assembly |
The fabrication process for MEMS devices is the epitome of exacting, painstaking effort, requiring the highest levels of intricacy and precision.
Built on technology developed to fabricate integrated circuits, the procedures for building MEMS must follow methodical rules and be carried out in a tightly controlled environment.
This requires very expensive, high fidelity robotic assembly lines operating in clean rooms with extremely low contaminant concentrations (one speck of dust could be the proverbial monkey wrench for these mechanisms).
As in the case of micro-chips, MEMS fabrication controls must be followed strictly for the devices to have any chance of carrying out their design functions once their fabrication is complete (“SAMPLES Program,” 2005).
Thus, in the design, fabrication, and operation of MEMS devices, it is clear that “small” is not synonymous with “simple” or “easy to understand or fabricate.”
As seen through the microscope, MEMS parts are easily as complex as their counterparts on the larger scale, if not more so. Furthermore, due to the strict requirements imposed by the meticulous fabrication process, the MEMS designer must exercise much more care in laying out the configuration of his design than would a designer working on a larger scale.
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The incredible MEMS clutch mechanism. The miniscule gears are 50 microns across. Keep in mind that there are 25,400 microns to an inch. |
To aid the designer in accounting for the tight constraints of a particular MEMS fabrication process, the developers of that process typically provide him a set of design rules to follow in laying out the design.
In turn, these rules usually are incorporated within the fabrication process itself through software that checks designs against these rules, and will not admit a design that violates them (“SAMPLES Program,” 2005). So, we see that the design rules and the fabrication process work together to produce devices that ideally will fulfill the desire of the designer throughout its operational life.
The design rules characterize fundamental aspects of the fabrication process and, thus, leave an indelible imprint of those process characteristics on each and every new design. These design rules, then, represent a bridge between the mind of the designer and the finished product, in a sense “guiding” the design through the fabrication process.
It is amazing that many of the engineers and scientists who have worked to make MEMS technology a reality believe that the vast, intricate, mechanical workings of the Universe, a Universe that appears to conform to immutable natural laws, came about through mostly random processes.
They have witnessed the microscopic complexity of MEMS, yet they admit reasoning that suggests the galaxies, solar systems, planets, and stars evolved from “simpler” particles of matter that somehow came into existence at the beginning of time. They hold these beliefs in spite of their understanding of the painstaking process that is required to design and fabricate a single MEMS mechanism.
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Fully-functioning MEMS transmission |
Scientists continue to discover with increasing clarity that the elementary particles of matter that make up everything in the observable Universe, though extremely small, are far from “simple.” In his book, A Brief History of Time, well-known physicist Stephen Hawking states:
Up to about twenty years ago, it was thought that protons and neutrons were “elementary” particles, but experiments in which protons were collided with other protons or electrons at high speeds indicated that they were in fact made up of smaller particles.
These particles were named quarks by the Caltech physicist Murray Gell-Mann, who won the Nobel prize in 1969 for his work on them.... So the question is: What are the truly elementary particles, the basic building blocks from which everything is made? (1988, p. 65).
Since science so far has been incapable of even identifying the most elementary components of the Universe, it is unreasonable to conclude that “small” means simple or easy. Given this unexpected complexity at the sub-microscopic (quantum) level, it is incredible that otherwise reasoned thinkers would conclude that everything we observe resulted from random processes.
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Close-up view of one vernier; the teeth are two microns wide and the spaces between them measure four microns. |
Likewise, small structures in biological study exhibit extremely high levels of order, complexity, and information content. Now that scientists actually are able to observe single-cellular life, accounts of the immense complexity in these “simple” life forms are becoming increasingly abundant. Consider Dean Overman’s summary of the research of Sir Fred Hoyle and Chandra Wickramasinghe in his monograph, A Case Against Accident and Self-Organization:
Because there are thousands of different enzymes with different functions, to produce the simplest living cell, Hoyle calculated that about 2,000 enzymes were needed with each one performing a specific task to form a single bacterium like E. coli.
Computing the probability of all these different enzymes forming in one place at one time to produce a single bacterium, Hoyle and his colleague, Chandra Wickramasinghe, calculated the odds at 1 in 1040,000. This number is so vast that any mathematician would agree that it amounts to total impossibility.... [T]he total atoms in the observable universe are estimated to be only approximately 1080 (1997, pp. 58-59, emp. added).
The performance observed in such a system (a bacterium) is so intricate and complex on such a small scale, that so far humans are incapable of duplicating it—MEMS is about as close as science has come to doing so. Yet, in stark contradistinction, many scientists seem to accept that a “simple” life form must have organized by accident and, in turn, given rise to all of the life that we observe on Earth.
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Complex MEMS ratchet mechanism |
The complexity inherent in MEMS, especially in comparison to larger scale systems, suggests a more natural conclusion regarding the existence of the Universe. If one were looking through a microscope in a science class, or working in a laboratory, and unexpectedly saw tiny gears turning or pistons moving, what would he conclude?
This scenario actually has been used as a story line in multiple science fiction shows, and the conclusion reached was not that the microscopic machines had evolved naturally through random processes. Besides the fact that such a conclusion might make for a rather boring story, it is simply an unsound conclusion under the circumstances.
Complexity on such a small scale, as we have noted, is not easy to design, so why would we ever conclude that it came about by accident? As in the science fiction scenario depicted, the intricate complexity that we observe on such a small scale is not only evidence of a designer, but also evidence of an incredibly advanced design capability—not of undirected random processes.
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The world’s smallest functioning triple-piston steam engine. One piston is five microns across or 1/5080 of an inch. |
The fact that the Universe operates under seemingly immutable natural laws is further evidence of a designer. We have noted that MEMS designers utilize design rules to ensure the viability of their designs.
While science has not fully characterized the rules that govern the Universe, or even proved their existence, scientists firmly believe in them. Countless observations and experiments have demonstrated that the Universe appears to behave in repeatable and predictable ways, indicating that there is an inherent yet unobservable constraint being enforced on that behavior.
Similar to MEMS design rules, the natural laws of the Universe determine what structures can viably exist in the system (Conservation of Matter and Energy), how they will behave (Causality, Laws of Motion, Relativity, etc.), and how long they will last (Thermodynamics). It simply is no more reasonable to assume that random processes gave rise to the behavior of the Universe than to assume that random fabrication processes could give rise to operational MEMS devices.
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Drive gear chain and linkages, with a grain of pollen (top right) and coagulated red blood cells (top left, lower right) to demonstrate scale. |
Indeed, experience with MEMS illustrates that the ordered complexity we observe at every level within the Universe, but especially on the small scale, is indisputable evidence of a Designer whose capability far exceeds human accomplishment.
MEMS research is impressive and fascinating, but pales in comparison to what we observe at the microscopic level, and what we theorize at the sub-atomic level.
The science and engineering of mankind has not come anywhere close to duplicating the intricate functional complexity that exists in the realm of nature’s small scale.
The Designer responsible for these micro- mechanisms fully understands the fabrication process parameters that are required to bring them into existence and sustain their operation, and has used that process to its utmost effectiveness in the creation of everything we observe.
Furthermore, the “design rules” that have been employed to accomplish this are nothing less than the natural laws that, in turn, continue to constrain and direct the ongoing operation of His design.
REFERENCES
Frechette, L.G., C. Lee, S. Arslan, and Y.C. Liu (2003), “Design of a Microfabricated Rankine Cycle Steam Turbine for Power Generation,” American Society of Mechanical Engineers International Mechanical Engineering Congress, International Meeting on Energy Conversion Engineering, pp. 335-344, November.
Hawking, Stephen (1988), A Brief History of Time: From the Big Bang to Black Holes (New York: Bantam).
McWhorter, Paul (2001), “Intelligent Multipurpose Micromachines Made at Sandia,” Sandia National Laboratories, [On-line], URL: http://www.sandia.gov/media/micro.htm.
McWhorter, Paul (2006), MEMS Image Gallery, [On-line], URL: http://www.memx.com/image_gallery.htm.
“MEMS Technology” (2006), [On-line], URL: http://www.memx.com/technology.htm.
Overman, Dean (1997), A Case Against Accident and Self-Organization (Lanham, MD: Rowman & Littlefield).
“SAMPLES Program” (2005), Sandia National Laboratories, [On-line], URL: http://mems.sandia.gov/samples.
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