HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Control Technology, Microelectronics and Nanotechnologycombination on a plastic card.In the automobile industry, cars use computer-controlled fuel injectionwhich is extremely efficient and speedometers can compute youraverage speed and remaining fuel and tell you in synthetic speech whengas is low. Headlights can come on automatically when the ambientlight falls below a certain level. Another use of computing is to calculatethe speed of the car traveling in front and specify if the two vehicles arebeing driven at a safe distance.Shrinking DevicesIt still remains a question how small actual devices can be made.Existing systems can be extrapolated to the 50 to 100 nanometer region.As you start getting wires, transistors and other components closer together,they start to talk to one another, and this crosstalk becomes aserious problem. The properties of the basic materials used (doped silicon)also become hard to control.It has seen from microelectronics that if you can make thingssmaller, there will be many applications for them. There is a need tomake things small so they can be fast and cheap and portable and notpower consuming.Photolithography that uses ultraviolet light to etch out patterns onsilicon chips is the dominant technology in making microelectronics onthe micrometer scale. Photolithography is getting more complex andcostly. The fabrication facilities for making semiconductor chips that arebeing planned now for the years past 2000, are estimated to be $3 billionto $10 billion. This means, that for a reasonable return on investment, agreater number of devices have to be sold every year for the few yearsthat this facility is the state of the art.Photolithography has been successful and there is every reason tothink this will continue for a while. It is hard to go below 100 nanometers,and you cannot build 3-D things yet. It does not work for many materialsother than silicon. One of the alternatives is electron beams. An exampleof this is Scalpel which is a system developed at Lucent Technologies’ BellLabs that uses electron beams to pattern silicon wafers.Another alternative is X-ray lithography. This process uses X-rays topattern wafers. Both of these have technical problems which will beworked out, but they may not be cheap enough in the end. Newer technologies,such as lithography, use neutral atoms or ion beams.©2001 by The Fairmont Press, Inc. All rights reserved.