A Look Toward the Future Of MEMS Technologies.
What do projection televisions, vehicle manifold pressure-sensing systems, and air bags have in common? All are equipped with and have been refined by MEMS, or microelectromechanical systems.
According to Sid Marshall, editor of R&D Magazine's "Micromachine Devices" newsletter, numerous products in the automotive industry, such as the sensing devices used for monitoring air pressure in carburetors, have had a large impact from MEMS and have been successful in bringing the level of credibility for microsystems up to speed.
The first of three hot buttons in the area of MEMS, according to Marshall, is optical communications. Nearly 15 years ago, Texas Instruments, Dallas, Texas, began developing a digital micromirror device that today is a MEMS technology that can be used in high-speed telecommunications, projection televisions, high-quality theater projection, and projectors that are connected to computers to display slide arrays on a screen.
This device consists of approximately 1,000 x 1,000 high-reflectivity mirrors, each placed in a 25-mm square rectangular array. "Imagine a panel with a bunch of little mirrors that can rock back and forth," says Marshall. "Each mirror and its degree of rocking is controlled by an electromechanical system underneath it. If a beam of light hits an element, that element can be reflected by the tilt Of the mirror. The beam coming in can be shifted out of the line of sight or can be shifted back in a specific direction. If you have 1,000 x 1,000 elements, you have a fine-grain way of projecting an image."
Researchers in fiber optics can also employ this technology in the newly begun broadband area. "As recently as this year, there were a few up-and-coming MEMS companies, like Cronos Integrated Systems, Research Triangle Park, N.C., and hundreds of different startups making optical components. Fiber-optic giants, like JDS Uniphase, San Jose, Calif., and Nortel Systems, Brampton, Ontario, have been looking for the correct hardware components--and micromirrors are just what they need to promote this technology."
Wireless communications is the second area that has come into the fore in microsystems. Cell phones and bluetooth technology, or short-distance wireless transmission for controlling computers and peripherals, are included in this area.
When integrated circuits were first created, there was much interest in doing radio-frequency circuitry and transmission. However, integrated circuits are basically 2-D devices, and in order to make RF devices, you have to have old fashioned coils and capacitors, says Marshall. Those devices were not available in microcircuit form.
"You can get around these problems with microsystem components because inductors and capacitors that are needed for making good RF circuitry are available in micro form," he says. "This is what Motorola, Ericsson, and Nokia all need in their telephones, and what was needed for PCs and PDAs to do high-speed wireless telecommunication."
The third area with enormous potential is biomedical systems and biotechnology at the microscale. One example is the laboratory on a chip, which uses microchannel fluidic devices to do chemical analysis on biosamples. Scientists envision a time when this technology will enable nontechnically trained staff or nursing aids in a point-of-care situation at hospitals to use a pinprick of blood to get a 150-component blood analysis.
"To some extent, there are devices to do this now," says Marshall. Researchers are doing blood gas analysis and analyzing sugar levels for diabetes control. The drug-delivery aspect is another possibility, as well as DNA analysis. "One technique, called polymerase chain reaction, allows a snippet of DNA to be replicated until you have enough to do a full analysis. In 15 min, you can do what would have taken 4 or 5 days nearly 6 years ago."
The biomedical component has taken off this year," says Marshall. "The area of drug delivery will have tremendous ramifications for all sons of therapeutic treatments."
Another primary interest for this technology is in forensic medicine. It enables researchers to replicate a very small blood or DNA sample and complete on-site analysis, pAnother area that is exploding with the use of microstructures is displays. Although LCDs have been adequate for the industry, users are clamoring for brighter-type displays and higher resolution.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||microelectromechanical systems|
|Comment:||A Look Toward the Future Of MEMS Technologies.(microelectromechanical systems)|
|Author:||Lewis, Sharon R.|
|Publication:||R & D|
|Article Type:||Brief Article|
|Date:||Dec 1, 2000|
|Previous Article:||IEDM Presents State-of-the-Art Nanotechnology.|
|Next Article:||Software For Scientists.|