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[sorry for the previous duplication - this version is formatted] Computer Scientists Are Poised for Revolution on a Tiny Scale SAN FRANCISCO - November 1, 1999 - Scientists at a variety of elite laboratories around the country are sharing a growing sense that they are on the brink of a new era in digital electronics. It will usher in a world of circuits no more than a few atoms wide, with a potential impact on computing, in terms of speed and memory, that may be too profound to fathom. It was only in July that a group of researchers at Hewlett-Packard and the University of California at Los Angeles reported that they had successfully fashioned rudimentary electronic logic gates -- a basic component of computing -- that were the thickness of a single molecule. Now other groups are preparing to announce that they have succeeded in creating other basic computing components at this ultramicroscopic scale, known as molecular electronics. Researchers at Yale and Rice Universities, for example, plan to report in the journal Science in a few weeks that they have taken an important step past the Hewlett-UCLA work. In the July demonstration, the molecular gate could be made to move into open or shut positions, but could not be switched back again. But the Yale-Rice team says it has created molecular-scale switches that can be repeatedly opened and shut -- a necessary step in representing zeros and ones, the basic binary signals used in the circuitry of digital transistors. And now Hewlett-Packard scientists say they have recently taken an important step toward creating rows of conductive wires that are less than a dozen atoms across -- a crucial part of hooking together the molecule-sized switches that could one day result in computers vastly faster than today's. The rapid sequence of breakthroughs is giving the researchers a new sense of confidence. "We're on the scent, and we know the fox is out there," said Stan Williams, a Hewlett-Packard physicist who is a pioneer in molecular electronics. According to the buzz in this research community, meanwhile, other laboratories are making progress on a number of fronts, working under top-secret conditions. One of these labs is said to be working on a molecular device capable of holding random-access memory, or RAM. If molecular memory devices could be constructed, they might offer vast storage capabilities for just pennies in cost. One near-term application might be to permanently store an entire DVD-quality movie in a space much smaller than a conventional semiconductor chip. As an applied science, molecular electronics would begin at a minute scale far beyond the theoretical boundaries of the conventional technology of silicon transistors. Today's silicon-based microelectronic devices have a minimum size between electrical components of 0.18 micron (about one-thousandth the thickness of a human hair) and could potentially go as small as 0.10 micron. That would be 100-billionths of a meter, or 100 nanometers. But in molecular electronics, the smallest components may be able to shrink to one-hundredth that size -- a single nanometer. The difference could mean chips exponentially more powerful than anything of a comparable size today or computing devices unimaginably tiny by contemporary standards. The recent rapid pace of advance has led to a palpable sense of mission among a small group of physicists, chemists and computer designers, who until recently were viewed as impractical dreamers by much of the computer industry. "In two to five years, you will begin to see functioning circuits which are of recognizable utility," said John Ellenbogen, a molecular electronics researcher at Mitre Corp., a research center for the military and private industry. Such optimism leads a number of researchers to believe that rapidly cascading advances in molecular-scale science may soon constitute what economists refer to as a disruptive technology -- one that changes basic industrial assumptions, just as the transistor did in replacing the vacuum tube during the 1950s, and as integrated circuits overtook individual transistors during the 1960s. Some molecular electronics researchers envision an entirely new industry, perhaps within the next decade. The consequences of such a revolution would be immense and possibly destabilizing for the world's semiconductor industry. Although the chip industry now believes that it sees a path at least until 2014 for making ever-smaller solid-state silicon devices, the cost of the manufacturing systems needed to make the chips is enormous -- and continuing to mount with each new chip generation. Today's semiconductor chips are made in multibillion-dollar fabrication plants -- or "fabs" -- that use light waves to etch successive layers of circuitry on a silicon substrate. It is an expensive process, in part because of the high cost of creating and maintaining the "clean rooms" required for avoiding contamination by dust. But researchers in molecular electronics are optimistic that they will be able to use much less finicky methods by creating chemical reactions that "self-assemble" vast numbers of molecular-scale circuits at infinitesimal cost. "This should scare the pants off anyone working in silicon," said Mark Reed, a Yale University chemist, who is co-author of the forthcoming Science article and co-leader of a related memory project to be announced Dec. 6 at the International Electron Device Meeting in Washington. "It will be dirt cheap and it will create a discontinuity." A colleague in the field agrees. "If you can make computers as easily as photographic film, then a lot of companies are going to be wondering what they're doing with their $15 billion fabs," said James Heath, a UCLA chemist who is part of the Pentagon-financed Hewlett-Packard-UCLA research team that demonstrated molecular logic gates last summer. The vision of a new industry has captured government and corporate attention. The Clinton administration is now considering the possibility of a National Nanotechnology Initiative as early as next January to set up financing and help organize diverse research activities in nanotechnology -- a range of manufacturing technologies that begin at the scale of individual molecules. Moreover, a number of computer and semiconductor companies, led by Sun Microsystems and Motorola, have been quietly meeting with scientists to discuss the formation of an industry consortium to seek commercial applications for molecular electronics. And yet, researchers acknowledge that so far they have taken only the first baby steps toward the larger challenge of building molecular-scale computers. No one, for example, has figured out how to interconnect billions and billions of molecular switches with wires 11 atoms in diameter. "It feels like we're a year before the invention of the transistor and we're asking: 'What does solid state look like?"' said Paul Saffo, a researcher at the Institute for the Future who has tracked the development of new technologies. And there is a general agreement that if such systems are to be assembled into workable computers, it will require radically new architectures alien to today's semiconductor-based computers. At Hewlett-Packard, at the Massachusetts Institute of Technology's Laboratory of Computer Science and at Mitre, computer scientists are beginning to explore computer architectures that are far more fault-tolerant than today's microelectronic computers and whose structures resemble biological systems. Manufacturing might involve assembling trillions of circuits and then identifying and mapping out the bad ones -- much as faulty sectors are declared off limits in today's disk drives. "We will try to program with what we've got," said James Tour, a molecular scientist at Rice University. "It's a very biological approach. Everyone's brain is the same, but the pathways are all unique." Much of the research financing in this field now comes from the Pentagon's Defense Advanced Research Projects Agency. "We've built this entire program on the idea of thinking differently," William Warren, a program manager at the agency, said. "We don't want to be standing on the shoulders of silicon." That is why the recent first steps toward eventual self-sufficiency have created such excitement in the molecular computing research community, a group that for years had a consistent vision but no empirical results. "All of us were constantly on the defensive," Ellenbogen, the Mitre researcher, recalled. "Although we believed in some rational way this was the way to go, among ourselves we were continually forced to reassure ourselves that we weren't crazy." By John Markoff Copyright 1999 The New York Times Company <http://www.nytimes.com/library/tech/99/11/biztech/articles/01nano.html> janet paterson 52 now / 41 dx / 37 onset 613 256 8340 po box 171 almonte ontario canada K0A 1A0 a new voice: <http://www.geocities.com/SoHo/Village/6263/> <[log in to unmask]>