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Nano machines: The tiny giants

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Nano machines: The tiny giants

From Diana J. Choyce
Feb 21 - 27, 2000

It may bring about a world of changes from science research to everyday chores

The old adage "bigger is better" has fallen by the wayside as new technologies prove it to be passe. From tiny CPU chips to shirt pocket cell phones, machines are simply getting smaller. And the smallest of these are the new nano machines. Nano technology has come a very long way in the last few years and these tiny giants may bring about a world of changes from science research to everyday chores. The possible applications of nano machines are varied and seemingly endless. In the medical field they could travel the human bloodstream, seek out and dissipate blood clots and clogged arteries. And then simply shut down and be eliminated when their work is through. Or they can be used to give sight to the blind through miniaturized sensors, which is already being researched and used in human trials. And in the computer field? A thinking, feeling machine that can anticipate your every need.

Ironically, a small New England university is at the forefront of this tiny technology. Worcester Polytechnic Institute and their Centre for Holographic Studies and Laser Micro-MechaTronics are studying machines so small, a microscope is needed just to see them. "What we are primarily specializing in is test measurement and optimization," says Dr. Ryszard J. Pryputniewicz who directs the project. "We seem to be the only people in the country, and the world, who can work at this level." MIT and the University of California also work in the same field but are using different approaches. "They have parts of what we have, and do an outstanding job, but we work with data in the full field of view," said Dr. P. Unlike other research efforts, WPI laboratories measure speed, deformation and a variety of characteristics of nano machines in real time. These machines have gears no bigger than a grain of pollen and can be

produced cheaply, in batches of tens of thousands at a time. And they are made from silicon, the same substance used by computer chips. "They are made on wafers (about the size of a vinyl long-playing record) and many, many of them can be made at the same time," said Dr. P. "Eventually you will have an entire laboratory on a chip. It will be able to measure position, velocity, acceleration, elevation, orientation, chemistry, whether something is environmentally safe or not... and you will be able to fine tune and control these processes. That's the goal."

WPI is working with industry and national laboratories such as Sandia in developing these tiny miracles. Sandia calls its project Micro Electro Mechanical Systems or MEMS, and is a recognized leader in the field. Their vision is a new silicon revolution which will enable chips to not only think, sense, and act, but communicate as well. They believe the market for these "intelligent" micromachine enhanced systems could well reach 100 billion a year. There are about 600 organizations working in the field, with 150 worldwide companies that are looking to find commercial market applications. Early uses include hydraulic-pressure sensors for aircraft flight-control systems that were developed by Honeywell in the 1960's. By the 1980 automakers began making similar sensors to monitor engine intake-manifold pressure in fuel-injected cars. Other applications were inkjet printer heads, and catheter devices for measuring blood pressure in surgical patients.

The real change took place in the mid 1980's when a production technique called surface micromachining was introduced. The method involves stacking layers of patterned and etched silicon structural material, which is acid-resistant, and alternating them with layers of a "sacrificial" silicon dioxide material that is dissolved away by hydrofluoric acid to create spaces between moving parts. What's left are tiny mechanisms that require no assembly, including gears that spin around hubs. This technique has promoted a leap in technology that is bound only by creativity. One use is tiny MEMS accelerometers that have drastically cut the cost of airbag controls. Another use is a device called Back Talk, made by Bio Kinetics Corp. of San Antonio. Designed to reduce the risk of workplace back injuries, the pager-sized gadget clips on the user's belt and issues an audio or vibrating alarm when he or she makes an ergonomically unsound move, such as lifting from the waist instead of from the knees. Texas Instruments in Dallas has developed a product exclusively devoted to producing its digital light processors (DLPs), which are MEMS chips packed with micromirrors. These chips are used in projection systems. A prototype of a DLP cinema projector, built by Digital Projection Ltd. of Atlanta, was recently demonstrated, which raises the prospect of commercial theaters switching from expensive film prints to movies delivered in electronic form. This advance could change the way we all watch TV and movies. And it is right in line with the new broadband developments on the internet in streaming video.

One can imagine that this technology is a wide open field. The future of applications and uses is secure because they will only be bound by our imagination and creativity. And we have been treading this path for decades. From massive gas hog cars to the small fuel efficient ones we know today. From computers that took up whole rooms to ones we can carry in our pockets. The move to nano technology was inevitable, and its time appears to be here and now.