ASM Materials Solutions 2000
Advances in Molecular Manufacturing

Description of Session

The purpose of this session is to provide the ASM materials community with relevant information on an important specialization of the diverse technological arena called "Nanotechnology." Molecular manufacturing refers to the production of complex structures via synthesis of materials and devices to atomic precision. Programmable, replicating assembler systems will enable the construction of macroscopic objects that are essentially atomically perfect. This technology, which is now being developed, and which has been bolstered this year by the $497 million National Nanotechnology Initiative, will have important consequences for the manufacture of both primary materials and finished products. The intended audience for this session is senior level corporate management involved in technology strategy, research directors in government institutions, conference attendees involved in technology policy, and academic researchers looking for new pursuits in materials synthesis or interested in education policy.

Invited:
1. Molecular nanotechnology: the long term goal: Ralph C. Merkle, Zyvex, Inc., Richardson, Texas.

Manufactured products are made from atoms. The properties of those products depend on the arrangement of those atoms. Today's manufacturing methods arrange atoms statistically, without control over the placement of individual atoms. Casting, milling, lithography, and other traditional "bulk" manufacturing technologies provide only approximate control over the molecular structure of the product being manufactured. In the future, we will be able to inexpensively manufacture products with almost every atom in its proper place. This will be essential for the manufacture of molecular computers, and will also let us make diamondoid structures of remarkable strength and lightness.

Invited:
2. Toward Computation as a Property of Matter: Progress Toward Molecular-Scale Electronic Computers: James C. Ellenbogen, Ph.D., Principal Scientist, Nanosystems Group, The MITRE Corporation, McLean, VA 22102.

In the not-too-distant future, computation will become a property of matter. Materials will be engineered to incorporate computation along with their other desirable structural properties, in much the same way that color is incorporated in and on the materials with which we now fabricate buildings, vehicles, and appliances. This outcome is a natural extension of recent demonstrations of molecular-scale electronic devices--i.e., wires and switches that are made from individual molecules. Eventually such devices and the computer circuitry made from them will become commonplace components of everyday objects, making them "smart" and sensitive to their environs. Even now, recent progress in molecular electronics research and development promises to surpass the rate and degree of miniaturization that is possible for conventional, solid-state microelectronics. The speaker will review and explain these exciting recent developments which promise to produce molecular-scale electronic computer circuits that will be as much as one million times smaller and denser than conventional microelectronics. Further, he will discuss how this trend and related trends in the manufacture of ultraminiaturized computers are likely to have a very significant impact on materials science. That is, he will explain how these developments toward nanometer-scale electronics also seem likely to produce a technology in which matter will acquire desirable physical and economic properties much like those of software.

Invited:
3. Nanotubes and Prospects for their use in Nanotechnology Systems: Prof. Rodney S. Ruoff, Dept of Physics, Washington University, St. Louis, MO 63130-4899

This talk will outline some prospective uses of nanotubes, particularly of carbon but also of boron nitride, in nanotechnology. Concepts including controlled mechanochemistry, nanopipette, and the mechanics of nanotubes, will be presented. This will be followed by a more detailed description of the mechanics of nanotubes as measured with new nanomanipulation tools. The tensile stiffness and strength, and the response to point indentation on the sidewall (local "squashing" and mechanical response to such applied load) will be presented. It will be seen that nanotubes offer interesting possibilities for positioning and control at the length scale of atoms.

Invited:
4. Using DNA to explore molecular self-assembly strategies: B. Yurke, Bell Laboratories, Murray Hill, New Jersey

A goal of nanotechnology is to construct complex structures, such as microprocessors, for which the components (e.g., wires and switches) would consist of single molecules. To accomplish this goal a fabrication technology must be devised which is versatile enough to allow the assembly of very complex structures yet also simple and robust enough to be manageable. Batch assembly in which all the components are poured into a vat where thermal diffusion and molecular recognition bring the appropriate parts together is an attractive approach. DNA, a linear polymer with a relatively predictable chemistry, is currently the recognition molecule of choice in studies of such fabrication strategies. In particular, two strands of DNA hybridize well only if their base sequences are complementary. This binding specificity with its large combinatorial space of distinct base sequences has been exploited in the assembly of a variety of structures, some of which perform molecular computation and some of which function as molecular motors. Several DNA-based molecular motors have been devised in my laboratory. Experimental work is currently being directed toward the fabrication of molecular-scale electronic circuits.

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Invited:
5. Molecular nanotechnology: developmental pathways: Ralph C. Merkle, Zyvex, Inc., Richardson, Texas.

In the last few years the goal of molecular nanotechnology has been accepted by the scientific and technical community, and has even become part of the President's National Nanotechnology Initiative. Serious questions remain, however, about how long it will take and how we can best pursue it. Answers are emerging, not only from academic and industrial research but also from start-ups that are betting significant sums that nanotechnology is going to be a major growth area. Charting a route from our present technology base to the future capabilities of molecular manufacturing involves a complex interplay of technical feasibility, funding, early products, and long term goals. There is no single right answer, as there are many technically feasible routesÑbut few of those many routes will be followed all the way to the goal. While developmental pathways must be technically feasible, those pathways that are less effective at providing customers, revenue, and clear intermediate goals that can stimulate funders and developers alike are less likely to win out in the Darwinian selection that is now starting.

6. Molecular Manufacturing Development and Technology Planning: David R. Forrest, Baverstam Associates, 85 Wells Ave., Suite 200, Newton, MA 02459, 508-820-0688; and also representing the Institute for Molecular Manufacturing, 555 Bryant Street, Suite 253, Palo Alto, CA 94301 , 650-917-1120.

Research and development of molecular manufacturing and related, enabling technologies is proceeding at an accelerating pace. The institutions that are doing this work, as well as their research as it relates to molecular manufacturing, are summarized in this talk. The general capability to synthesize macroscopic objects and devices to atomic specification brings with it some surprising and important consequences, which are outlined in this presentation. With order-of-magnitude performance improvements that are predicted for materials and devices, molecular manufacturing is now receiving attention at the highest level of government in the United States (and elements of it have been a national priority in Japan for over 10 years). Although determining the exact timing of the "assembler breakthrough" remains a speculative exercise, corporations can adopt strategies to avoid being blindsided by nanotechnology development (as were pharmaceutical companies by biotechnology). Industry can cooperate with governmental institutions, educational institutions, professional societies and standards organizations to (a) focus research priorities appropriately, (b) insure the adequate training of scientists, engineers, and technologists, (c) address public safety and environmental concerns, and (d) address national security concerns. Policy formulation will be an ongoing challenge, although new tools can improve the process of critical discussion and debate.