| Term Papers Count: 63,000 | ||
| Home | Join | Login | Logout | Forgot Password | FAQ | Contact | ||
|
| ||
Term Papers on Organic Molecules Challenge
Organic Molecules Challenge Silicon's Reign as King of Semiconductors There is a revolution fomenting in the semiconductor industry. It may take 30 years or more to reach perfection, but when it does the advance may be so great that today's computers will be little more than calculators compared to what will come after. The revolution is called molecular electronics, and its goal is to depose silicon as king of the computer chip and put carbon in its place. The perpetrators are a few clever chemists trying to use pigment, proteins, polymers, and other organic molecules to carry out the same task that microscopic patterns of silicon and metal do now. For years these researchers worked in secret, mainly at their blackboards, plotting and planning. Now they are beginning to conduct small forays in the laboratory, and their few successes to date lead them to believe they were on the right track. "We have a long way to go before carbon-based electronics replace silicon-based electronics, but we can see now that we hope to revolutionize computer design and performance," said Robert R. Birge, a professor of chemistry, Carnegie- Mellon University, Pittsburgh. "Now it's only a matter of time, hard work, and some luck before molecular electronics start having a noticeable impact." Molecular electronics is so named because it uses molecules to act as the "wires" and "switches" of computer chips. Wires, may someday be replaced by polymers that conduct electricity, such as polyacetylene and polyphenylenesulfide. Another candidate might be organometallic compounds such as porphyrins and phthalocyanines which also conduct electricity. When crystallized, these flat molecules stack like pancakes, and metal ions in their centers line up with one another to form a one-dimensional wire. Many organic molecules can exist in two distinct stable states that differ in some measurable property and are interconvertable. These could be switches of molecular electronics. For example, bacteriorhodpsin, a bacterial pigment, exists in two optical states: one state absorbs green light, the other orange. Shinning green light on the green-absorbing state converts it into the orange state and vice versa. Birge and his coworkers have developed high density memory drives using bacteriorhodopsin. Although the idea of using organic molecules may seem far-fetched, it happens every day throughout nature. "Electron transport in photosynthesis one of the most important energy generating systems in nature, is a real-world example of what we're trying to do," said Phil Seiden, manager of molecular science, IBM, Yorkstown Heights, N.Y. Birge, who heads the Center for Molecular Electronics at Carnegie-Mellon, said two factors are driving this developing revolution, more speed and less space. "Semiconductor chip designers are always trying to cram more electronic components into a smaller space, mostly to make computers faster," he said. "And they've been quite good at it so far, but they are going to run into trouble quite soon." A few years ago, for example, engineers at IBM made history last year when they built a memory chip with enough transistors to store a million bytes if information, the megabyte. It came as no big surprise. Nor did it when they came out with a 16-megabyte chip. Chip designers have been cramming more transistors into less space since Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor first showed how to put multitudes on electronic components on a slab of silicon. But 16 megabytes may be near the end of the road. As bits get smaller and loser together, "crosstalk" between them tends to degrade their performance. If the components were pushed any closer they would short circuit. Physical limits have triumphed over engineering. That is when chemistry will have its day. Carbon, the element common to all forms of life, will become the element of computers too. "That is when we see electronics based on inorganic semiconductors, namely silicon and ga... This is ONLY a preview of the article. If you would like to view the entire document, you must subscribe to Digital Term Papers. Please register below now! Digital Term Papers has over 63,000 essays, term papers, and book notes online. Many paper sites will charge you hundreds of dollars for a single paper. Digital Term Papers only charges $14.95 for a one month membership with instant account activation! Don't waste anymore time! Join NOW!!!
|
|
Copyright 1998-2007 Digital Term Papers. All Rights Reserved.
Forgot Password
Cancel Account
Privacy Policy
Disclaimer
Contact Us
Essay List: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |