|Foresight Update 39 - Table of Contents|
Progress in the field of molecular electronics has accelerated sharply in recent weeks and months, and the gathering momentum toward practical applications has garnered considerable media attention. A major article appeared in the New York Times on 1 November 1999 ("Computer Scientists Are Poised for Revolution on a Tiny Scale" by John Markoff).
While the article presents few technical details of current advances occurring in molecular electronics research, it does capture some of the mood what Foresight Webmaster Jim Lewis has described as "an imminent revolution."
"Scientists at a variety of elite laboratories around the country," Markoff begins, "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."
The article touches on a wide range of research efforts, including the announcement last summer of a molecular logic gate by a team at Hewlett-Packard Labs and the University of California at Los Angeles (see "Media Watch 38", last issue). The article also hints at other advances to be announced by other research teams. James C. Ellenbogen, a prominent molecular electronics researcher at Mitre Corp. is quoted as saying, "In two to five years, you will begin to see functioning circuits which are of recognizable utility."
Describing the self-assembly to cheaply fabricate molecular-scale circuits, Mark Reed, chairman of the electrical engineering department at Yale University, is quoted as saying "This should scare the pants off anyone working in silicon."
Reed was not speaking speculatively. One of the limitations of the HP/UCLA discovery was that the configuration of molecular devices could only be switched once. But the very same day, Yale University issued a press release announcing that a collaborative team led by Reed and James Tour of Rice University's Center for Nanoscale Science & Technology had demonstrated "a memory element the size of a single molecule." Unlike the HP/UCLA system, the Yale/Rice molecular switch can be switched reversibly. A full report on the discovery by Reed, Tour and two of their graduate student researchers ("Large On-Off Ratios and Negative Differential Resistance in a Molecular Electronic Device") was published in the 19 November 1999 issue of Science.
James Tour and Rice University, a bit more restrained, waited until the Science paper appeared before issuing their press release. Although much work remains to be done to create a practical computing device, Tour cautioned, he concluded, "It really looks like we're going to have hybrid molecular- and silicon-based computers within five to ten years."
Detailed results are to be presented at the International Electron Devices Meeting in Washington, D.C. on 6 December 1999.
A Reuters news service article on the Yale-Rice team's work ("Second U.S. Team Takes Step Toward Tiny Computer," by Maggie Fox, 19 November 1999) appeared in several publications. Versions from the New York Times and the San Jose Mercury News.
Additional reports of the increasing pace of advance in molecular electronics research appeared elsewhere:
The first hour of National Public Radio's Talk of the Nation: Science Friday on 5 November was devoted to the topic of New Computing Technologies. While some of the discussion dealt with IBM and Intel development of advanced semiconductors and flexible (polymer) bulk organic conductors, there was also much discussion of molecular electronics. One guest was Yale's Mark Reed. A RealAudio file of the show is available on the Science Friday web site.
"A molecular electronics research project at Mitre Corp. has achieved a milestone in the effort to build self-assembled molecular computers. Researchers James Ellenbogen and Christopher Love have invented chemical building blocks that support the operation of a digital half adder, which represents a new level of circuit complexity for the field."
The MITRE device is only a design; it has not yet been synthesized or tested. However, according to their report, the "circuit" the MITRE researchers have designed is a complex molecule that includes "only experimentally demonstrated molecular electronic devices as their components." They add, "The corresponding conductive molecules, if realized, would use much less power and also would be as much as one million times smaller in area than the comparable circuits on a state of-the-art commercial microcomputer chip."
The article says the next goal of the research at Mitre is to find a chemical recipe for a three-terminal transistor, opening the door to truly complex logic devices. One advantage to this type of device, which includes the Yale/Rice switch above, is that they could potentially be mass produced via chemical synthetic self-assembly, rather than painstakingly built using manipulators like atomic force microscopes.
Brown correctly points out, "The one drawback to that scenario is the problem of random defects . . . While molecular structures can self-assemble with a high degree of accuracy compared with human-directed processes, the sheer number of units means that even a small probability of error will result in many defects. And, at the molecular scale, a defect can break a connection or render a junction inoperable."
One approach to this problem is to develop fault-tolerant circuit designs, to find circuit architectures that will be able to function accurately even with a given level of random defects. This is the approach being taken by the HP/UCLA team.
For a technical summary of this work, see Jeff Soreff's "Recent Progress," in this issue. A copy of the Mitre report Architectures for Molecular Electronic Computers. 1. Logic Structures and an Adder Built from Molecular Electronic Diodes, by James Ellenbogen and Christopher Love (MITRE Corp., July 1999), can be downloaded as an Adobe Acrobat PDF file.
An article in the 11 September 1999 issue of Science News ("Molecular motors spin slowly but surely," by Corinna Wu) covered two papers demonstrating prototype synthetic molecular motors which appeared in the September 9 issue of Nature ("Unidirectional rotary motion in a molecular system," by TR Kelly, H De Silva and RA Silva of Boston College; and "Light-driven monodirectional molecular rotor," by N Komura, RWJ Zijlstra, RA van Delden, N Harada, and BL Feringa of the University of Groningen in the Netherlands and Tohoku University in Japan). Again, for a technical summary of these two papers, see Jeff Soreff's "Recent Progress," in this issue.
An article on the Boston College motor work, syndicated by the Christian Science Monitor ("One billion of these motors would fit in a single human cell," by Alex Salkever) appeared in various publications, including the 19 September 1999 Schenectady, New York Sunday Gazette. While focusing on the motor itself, the article briefly discusses broader nanotech-related issues.
The molecular motor demonstrations were also noted by various reports on Web news sites, including ABC News and BBC News. Among them, Wired News ("The Tiniest Motor Ever") quotes K. Eric Drexler, senior research fellow at the Institute for Molecular Manufacturing: "Though these first artificial molecular motors are too slow and underpowered, their successors will enable a host of applications in molecular robotics, manufacturing, and medicine."
A special issue of Time Magazine focused on the theme "Beyond 2000: Your Body, Our Planet" (8 November 1999). An article titled "Will Robots Make House Calls?" dealt with the theme of robotic medicine. A sidebar, "...and Will They Go Inside Us?", covered the possibility of medical nanorobots. The illustrated sidebar seemed to assume their development was a short-term certainty, and described the possibilities of nanomedicine in a positive light.
An op-ed piece in the 18 October 1999 issue of the Washington Post, by former House Speaker Newt Gingrich ("We Must Fund The Scientific Revolution"), calls for a doubling of federal spending on scientific research in the next five years. Gingrich cites nanotechnology as one of five areas in which "major scientific breakthroughs that will transform our lives." He continues, "Consider a few of the stunning possibilities: ... Nanotechnology, the science of developing tools and machines as small as one molecule, will have as big an impact on our lives as transistors and chips did in the past 40 years. Imagine highly specialized machines you ingest, systems for security smaller than a piece of dust and collectively intelligent household appliances and cars. The implications for defense, public safety and health are astounding." The American Institute of Physics reprinted the piece on the web as a Bulletin of Science Policy News.
A special issue of the web-based FEED Magazine on 21st Century Inventions includes a long essay on nanotechnology by Mark Pesce ("Thinking Small," 8 November 1999). Pesce's essay explores the roots of nanotechnology in Richard Feynman's famous 1959 talk, through Marvin Minsky's thinking about the future during the 70's, leading to Eric Drexler crafting his ideas about nanotechnology and spreading them to his fellow students at MIT, leading to the publication of Engines of Creation. Pesce also comments on progress described at last month's Seventh Foresight Conference on Molecular Nanotechnology, and on the recent publication of Robert Freitas's Nanomedicine, and then compares the state of nanotechnology today with the early days of the personal computer revolution:
An article syndicated by the Knight Ridder Newspapers ("Ultra-tiny machines are becoming big hope for scientists") appeared in numerous papers, including the San Jose Mercury News, and described the growing importance of nanotechnology: "Government agencies, leading universities and major corporations are rapidly expanding their efforts to design and build machines and structures on the scale of atoms and molecules." The article quotes Rice University's Richard Smalley and others who testified during recent Congressional hearings on increasing funding for nanotechnology (see Update 37), then points to research in molecular motors by Cornell's Carlo Montemagno and T.R. Kelley at Boston College (see above), to the molecular wheels demonstrated by James Gimzewski at IBM, to the "nanopen" work of Chad Mirkin at Northwestern University (http://www.foresight.org/hotnews/archive1.html#Nanoplotter). Medical applications are mentioned. The article concludes the consensus of researchers seems to be that "nanotechnology stands today where television was in the 1930s and transistors in the 1950s."
In his column of 15 October 1999 ("Nanotechnology: from science fiction to fact"), Dan Gillmor, Mercury News Technology Columnist, writing immediately before the opening of the Seventh Foresight Conference on Molecular Nanotechnology, concluded that nanotechnology is moving solidly into the realm of mainstream science.
An extensive and informative general-interest article on nanotechnology and other new technologies appeared in the Christian Science Monitor ("The brave new world of biotechnology and beyond," by Peter N. Spotts, 28 October 1999). Interestingly, this article also begins with the example of Carlo Montemagno of Cornell University as well as Viola Vogel of the University of Washington adapting biological motor molecules for use in artificial molecular machines to highlight "one of the most far-reaching themes emerging from half a millennium of advances in physics, biology, and chemistry. Science is giving humanity the knowledge and the tools to manipulate and mix matter at its most fundamental levels to yield uniquely human combinations of form and function."
The article also discusses issues related to biotechnology and microtechnology, primarily as technological antecedents to the development of nanotechnology. Strong basic background information (size scales, Feynman's 1959 talk) is given to put today's research in perspective. Once again, Nobel laureate Richard Smalley of Rice University is quoted: "I'm convinced that the next century is going to make this century seem rather calm by comparison," Dr. Smalley says. "What we've done so far has not really harnessed the power that one will get when one can really put atoms where one wants to put them."
To emphasize the importance of nanotechnology research, the article cites a general interagency effort, led by the National Science Foundation, to double U.S. government funding for nanotechnology to $500 million annually over the next three years. The article provides some thoughtful discussion, with such leading figures as Nobel laureate Richard Smalley, on dealing with the potential impacts of current and developing technologies:
"As the currents of biotechnology and nanotechnology cross and mingle, the ethical debates that have accompanied issues such as cloning and ownership of living organisms are likely to intensify. 'One wonders where all this is leading,' acknowledges Smalley. 'The road we're passing down could be a road that ends up developing new life forms. Maybe we would be part of those, or maybe we would be bystanders just looking at them. That should get the ethicists amongst us working. It will be possible, it seems almost inevitable, to vastly extend the length of human life. I suspect it will be possible to pretty well eliminate most forms of disease, so the result on global population will be incredible.'
"Coming to terms with benefits and potential risks of biotechnology and nanotechnology involves balancing market values with other human values, according to Rachelle Hollander, who directs the Societal Dimensions of Engineering, Science, and Technology program at the National Science Foundation. 'Ethical debates have not stopped technologies from being developed,' she says. "But understanding the potential harm has changed the way they are implemented.' "
Some additional examples of the difficulties seen in the introduction of genetically engineered crops and foods were discussed, and reaches the conclusion: "This interplay between science, technology, and the public will increase . . . Citizen involvement in decisions to implement new technologies is likely to grow."
A special report ("How Nanotechnology Will Change the World," By Alicia Neumann and Kristina Blachere) appeared on the CNET web site on 20 October 1999. The report describes how molecular nanotechnology "will change the world in ways we can barely begin to imagine" during the next 50 years. Assemblers will revolutionize manufacturing by precisely manipulating atoms and molecules, as computers manipulate digital bits, to build complex objects, including copies of themselves. The results will range from "the end of disease; even immortality" to "specialized killing machines that could be built and dispatched in a day." The article concludes "The road to mastering nanotechnology may be long and winding, but there is no doubt that getting there will be interesting."
From Foresight Update 39, originally published 30 December 1999 .
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