Eighth Foresight Conference Shows Nanotech 'Coming Into Its Own'
Diversity of presentations highlights expanding academic, government and private sector involvement
by Jim Lewis
The Eighth Foresight Conference on Molecular Nanotechnology opened with senior conference Co-Chair Jan Hoh giving voice to the pervasive feeling that this year nanotechnology is coming "into its own." The single event that has crystallized interest in nanotechnology among the mainstream scientific community was the announcement in January of the U.S. National Nanotechnology Initiative (see Update 40).
In a departure from recent practice, the keynote speaker this year was not a Nobel laureate speaking on progress in one area of nanoscale science and technology. Rather an inventor and successful entrepreneur in the area of artificial intelligence systems, and a winner of the 1999 National Medal of Technology Award, Raymond Kurzweil of Kurzweil Technologies, Inc. surveyed the coming century from the standpoint of "The Law of Accelerating Returns." Noting that a wide range of technologies are progressing at double exponential rates, Kurzweil expects the 21st century to witness 20,000 years of progress at today's rate of progress. Similarly, all of the progress of the 20th century only equals 25 years at today's rate. Consequently when a Harvard Nobel laureate predicts that we will not see mature nanotechnology for 100 years, he is ignoring the fact that it will only take 20 to 30 years to achieve the equivalent of a century of today's progress. A corollary conclusion is that relinquishment of nanotechnology, as advocated by Bill Joy (see Update 41), is infeasible because nanotechnology will arise from gradual progress in many fields, not isolated development in one field.
Long-term double exponential growth results from a succession of paradigm shifts in technologyas one technology runs out of steam, a paradigm shift introduces a new technology, resulting in a series of "stacked S-curves". By Kurzweil's reckoning, Moore's Law represents the 5th paradigm for computing, and molecular computing will be the 6th. Kurzweil anticipates that progress in computation, miniaturization of technology, biotechnology, and scanning and reverse engineering of the human brain will result in an inexpensive computer ($1000) with the raw computational capacity of the human brain by 2020, and with the computational capacity of all human brains on earth by 2050. Nanobots circulating in the blood stream and embedded in the human brain will not only cure diseases and greatly increase longevity, but will also greatly augment human senses and cognition. The end result of these trends will be that by the end of the 21st century, humans and their machines will be merged.
Charles Lieber of Harvard Univ. discussed building tools and devices for nanotechnology using carbon nanotubes (CNT) and semiconductor nanowires. An important class of new tools are improved CNT tips for scanning probe microscopes (SPM) that would greatly improve resolution by reducing the radius of curvature of the tip from the 5 nm radius typical of current tips to a fraction of a nm. Previously, to use CNTs as SPM tips required using bundles of individual CNTs and tediously mechanically placing each CNT bundle on a tip. Lieber reported using chemical vapor deposition (CVD) to grow arrays of CNT tips varying from 2 to 0.8 nm in diameter, according to the growth conditions and catalyst particle chosen. Improvements expected soon include exploiting the difference in chemistry between the tip and sides of CNTs to localize specific molecular groups at the tip. Such tips should be precise enough to scan protein surfaces for specific binding domains, or to look at variations between DNA sequences. Lieber also used catalyst particles to grow well-characterized nanowires from semiconductors like silicon and indium phosphide, and showed that these nanowires can be doped to control conductivity over five orders of magnitude. Bistable switches were constructed by suspending a CNT bundle (or "rope") above another CNT rope lying perpendicular to the first one. The ON and OFF states of the switch are determined by whether or not the two CNTs are in van der Waals contact with each other, and these states are non-volatile. Calculations indicate that such arrays of CNTs and nanowires could be used to build both memory and logic devices with 100 GHz speeds and Tbit/cm2 densities. Complex devices could be built by hierarchical assemblyfor example combining self assembly of molecular building blocks with micro-fluidics, in which laminar flow would be used to align a series of nanowires, followed by rotation by 90 degrees and more laminar flow to align a second series of nanowires at right angles to the first.
Another type of molecular building block was proposed by James T. Spencer of Syracuse University. Citing the desirability of designing chemical subunits that can use chemical forces to assemble into larger units, Spencer described the advantages of "molecular synthons" composed of polyhedral boron clusters. These are rigid, thermally stable, have a wide range of chemical and electronic properties, and utilize pi-electron stacking between aromatic rings to create a wealth of molecular architectures, including rings, rods, and helices.
Scientific surprises still await investigators as nanofabrication techniques enable experiments that were not previously possible. Robert Celotta of the National Institute of Standards and Technology (NIST) reported studies of magnetization of iron whiskers lying upon a wedge of chromium atoms 0 to 20 nm thick. Surprisingly, the magnetization was found to reverse with every added atomic layer of chromium (0.124 nm thick); every 20 layers the reversal did not occur.
Andres Oberhauser of the Mayo Clinic used an AFM (atomic force microscope) to mechanically unfold a single protein molecule anchored to a gold substrate. Titin is the longest protein in the human genome. A 1-micron long molecule is composed of hundreds of 90-amino acid domains, each of which extends 28.5 nm as it unravels under a force of 200 pN. The domains have similar 3D structures and similar mechanical unfolding properties even though the domains do not have the same amino acid sequence. The mechanical properties of the domains could be altered by inserting additional amino acids at various positions within the domain, or replacing certain amino acid residues with a different amino acid. Some mutations would increase force needed to unravel a domain; others would decrease the needed force. After being pulled out with the AFM, the protein could refold in about a second. The process is reversible since one protein could be relaxed and re-stretched repeatedly for an hour.
Klaus Schulten of the University of Illinois at Urbana-Champaign showed how the mechanical stretching of titin could be modeled using steered molecular dynamics, in which external forces are applied to reduce energy barriers between conformations. Further, Schulten demonstrated how the increasing power of computational methods can model more complex, supramolecular nanosystems, describing how light interacts with the purple membrane (PM) of Halobacterium and with the photosynthetic unit (PSU) of purple bacteria. The computational tools used include NAMD a parallel, object-oriented molecular dynamics code designed for high-performance simulation of large biomolecular systems, VMD a molecular visualization program for displaying, animating, and analyzing large biomolecular systems using 3-D graphics, and BioCoRE, a collaborative research environment. The PM unit cell contains 3 protein bacteriorhopsin molecules, 28 lipid molecules, and 8410 water molecules, and its structure is known in atomic detail. Simulation demonstrates how photo excitation of the chromophore in the bacteriorhopsin displaces water molecules, providing a mechanism for pumping protons across the membrane, thus converting light energy into a proton gradient. The PSU is an even more complicated structure, consisting of a photosynthetic reaction center and several associated light harvesting complexes, each containing multiple pigment-protein complexes. The atomic structure of the entire PSU has been determined from a combination of crystallography and modeling studies, forming a basis for studying energy transfer in the photosynthetic membrane, and for studying how these multi-protein complexes self-assemble in the membrane. A remaining challenge is to exploit knowledge of nature to build technical devices.
One way to manipulate biological molecular motors was demonstrated by Peter G. Gillespie, Oregon Health Sciences University. Working with the myosin I-beta molecule found in cilia of hair cells in the inner ear, Gillespie constructed a mutation that worked normally but was inhibited by a molecule that had little effect on the normal myosin, opening the possibility of independent control of separate molecular motors through adding different solutions.
Foresight Institute Awards 2000 Feynman Prizes in Nanotechnology
Communications Prize and Distinguished Student Award are also presented
Winners of the 2000 Feynman Prizes in Nanotechnology: Uzi Landman of Georgia Tech (left), Philip Kuekes of HP Labs (center), and James Heath of UCLA. Stanley Williams of HP Labs was unable to attend the awards ceremony.
Two Prizes are given annually, one for theoretical work and one for experimental achievement.
Georgia Tech physicist Uzi Landman won this year's Feynman Prize in Nanotechnology (Theoretical) for his pioneering work in computational materials science for nanostructures. Such computer modeling provides deep insights into the nature and properties of matter at the nanoscale, and is essential in predicting what could be built at the molecular level, reducing time spent on expensive "wet" lab experiments.
The Experimental Prize went to the multidisciplinary team of chemist R. Stanley Williams and computer scientist Philip Kuekes, both of HP Labs in Palo Alto, along with chemist James Heath of UCLA. They were cited for building a molecular switch, a major step toward their long-term goal of building entire memory chips that are just a hundred nanometers wide, smaller than a bacterium.
The Feynman Prize in Nanotechnology is named in honor of the late Nobel physicist Richard Feynman, whose visionary talk in 1959 continues to inspire today's nanotechnology R&D community.
First Foresight Prize in Communications Presented
Ron Dagani, Senior Correspondent for Chemical & Engineering News, was named the winner of the Foresight Prize in Communications, which was awarded for the first time this year.
Dr. Dagani was selected for extensive coverage of nanotechnology and nanotechnology-related research over the past three years in Chemical & Engineering News, the widely-read weekly newsmagazine of the American Chemical Society.
Dagani holds a Ph.D. in organic chemistry from MIT and was an NIH Postdoctoral Fellow in toxicology, also at MIT. Previous honors include being named an AAAS Mass Media Science & Engineering Fellow.
The Foresight Prize in Communications recognizes outstanding journalistic or other communication endeavors that lead to a better public understanding of molecular nanotechnology or other key emerging technologies of high social or environmental impact.
By offering the Communications Prize, Foresight hopes to encourage continued responsible coverage of molecular nanotechnology and other emerging technologies as a means for engaging the public in dialogue leading to improved public policy on these important issues.
Special thanks go to the law firm of Millstein & Taylor, which underwrites the Prize, and to Foresight Senior Associate Larry Millstein of that firm, who initiated this program.
Mr. Love was selected for his work in architectures for molecular electronic computers and nanomanipulation of structures on surfaces. He has contributed to nanotechnology research for seven years at three major U.S. research laboratories, starting in MITRE's Nanosystems Group at age 16.
The Foresight Institute Distinguished Student award provides a $1500 grant to the college graduate or undergraduate student whose work is deemed most notable in advancing the development and understanding of nanotechnology.
The award, provided this year through the generosity of entrepreneur Jim Von Ehr of Zyvex Corp., and Ravi Pandya of IECommerce Inc., is intended primarily to enable the winning student to attend Foresight Institute's Conference on Molecular Nanotechnology, which is held annually to bring together leaders in nanotechnology research.
The Eighth Foresight Conference On Molecular Nanotechnology
Conference Co-Chairs Prof. Don Brenner (left) of North Carolina State University, and Prof. Jan Hoh of Johns Hopkins University, obviously pleased with the success of their efforts.
Conference Keynote speaker Ray Kurzweil answers questions following his presentation
Tutorial Chair Prof. Susan Sinnott of University of Florida
Glenn H. Reynolds, a member of the Foresight Board of Directors
Robert A. Freitas Jr., Research Scientist at Zyvex Corporation, and author of Nanomedicine
The information table of the National Institute for Standards and Technology (NIST) was just one indication the increased government interest in nanotechnology since the National Nanotechnology Initiative was announced. A number of researchers from federal labs also presented at the conference.
Distinguished Student Award winner Christopher Love (left), with James C. Ellenbogen of MITRE Corp., where Love began his studies of nanotechnology as a high-school intern. Love and Ellenbogen collaborated on a number of significant studies of molecular electronics device properties and designs.
A group of conference attendees takes a breather following the evening poster session. In back row: Philip Kuekes (left), a Feynman Prize recipient; Elaine Tschorn; Conference Co-Chairs Jan Hoh and Don Brenner; Foresight Update Editor Richard Terra. Middle row: Marcia Seidler (left); Tutorial Chair Susan Sinnott; Tanya Jones; and Deepak Srivastava, a Co-Chair of the 1999 Conference. Seated: Ralph Merkle of Zyvex (left); and Bill Goddard of Caltech.
Nobel Laureate in Chemistry Prof. John Polanyi, Univ. of Toronto, and Keynote speaker at the 1999 Foresight Conference
This year's poster session was marked by the sheer number of presenations, the high quality, and as can be seen from these pictures the interest and intense interaction it generated among the attendees.
Left: A trio of pleased conference regulars (left to right): Rich Colton of Naval Research Laboratory, Deepak Srivastava of NASA/Ames, and Philip Russell from North Carolina State University
Right: Some of the conference presenters gather during the poster session: Jacqueline Krim, a physicist at North Carolina State University (left), James Batteas and Charles Drain of CUNY, and chemist Paul Weiss of Pennsylvania State University.
Left: David Forrest, a long-time Foresight Friend, and currently President of the Institute for Molecular Manufacturing.
Right: Ralph Merkle, Principal Fellow at Zyvex Corporation, and a member of the Foresight Board of Advisors.