The Potential of Nanotechnology for Molecular Manufacturing

Max Nelson, Calvin Shipbaugh

RAND Copyright © 1995

Preface

This research was undertaken to explore the potential for advanced manufacturing based on molecular nanotechnology. This report provides a framework for understanding the scope of this topic--possible benefits, development risks, and policy options--but it is not the intention of the authors to provide a definitive road map (with corresponding technical assessments); nor is it believed by the authors that such a detailed analysis would at present yield a fully credible road map. Rather, it is the contention of the authors that much basic and applied research needs to be undertaken to realistically assess the far-term viability of many of the most interesting emerging concepts, but a careful and objective feasibility assessment could help stimulate near-term achievements and prevent technological surprise by foreign players. The authors anticipate that the framework and analysis presented herein could provide useful and objective input into such a technology assessment.

RAND supported this research as part of its corporate-sponsored research program. This report should be of interest to policymakers, scientists, and other individuals involved in the fields of nanotechnology and molecular manufacturing.

Summary

Nanotechnology--a term introduced in 1974 to describe ultrafine machining of matter--has come to be applied to a wide scope of small-scale engineering. With nanotechnologies, two activities are possible--nanomeasurement and nanomanipulation. Molecular manufacturing is the willful use of these two activities to create objects. Proponents of the application of nanotechnology to molecular manufacturing suggest that environmentally clean, inexpensive, and efficient manufacturing of structures, devices, and "smart" products based on the flexible control of architectures and processes at an atomic or molecular scale of precision may be feasible in the near future (i.e., 10-20 years from the present). The ambitious goal is to produce complex products on demand using simple raw materials; e.g., inserting the basic chemical elements in a molecular assembly factory to yield a common household appliance, perhaps with sensors and actuators built-in to respond to commands or environmental conditions. The question of whether it is possible to achieve a stage in the foreseeable future when such extreme capability might be viable, and if so how to develop the field, is a point of contention in both scientific and policy circles.

The concept of manufacturing at the "nano" or atomic scale dates to more than three decades ago. Many developments in biotechnology, chemistry, computational tool building, electrical engineering, and physics have moved the scientific and engineering community closer to operating smoothly on the nanoscale. In addition to extensions of micromachining--with production methods such as lithography, commonly encountered for microelectronics or microelectromechanical systems (MEMS)--there have been recent developments in scanning force microscopes (SFM), using probes that can position atoms or molecules to nanometer scales, and interest in investigating the means by which complicated molecules with desired properties can be modeled, synthesized, and perhaps even self-assembled. These recent developments have motivated advocates of a "bottom-up" approach for manufacturing molecule-by-molecule.

Exclusive use of this approach however, misses the longer-lived history and some of the benefits being achieved through the more familiar "top-down" approaches. The top-down approach is one in which macroscale components are utilized to create nanoscale structures. This differs from the bottom-up approach, which uses nanoscale components to create structures. In particular, top-down structures and methods might help with the interfacing of bottom-up structures into a system. Cases to support this position include chemical sensors that use microelectronics technology, biosensors that use enzymes and electrodes, and the potential of protein-based memory in an optical holography system.

Useful means of positioning and interconnecting molecular structures might be created in the near term that could serve as a proof-of-principle that more ambitious molecular manufacturing may be possible. If meaningful molecular assembly (or more extensive modeling tools for rational molecular design) is not demonstrated in the next decade, then the field of molecular nanotechnology may well have encountered an impasse that will challenge the credibility of the practicality of molecular nanotechnology for a revolution in manufacturing concepts.

Extensive molecular manufacturing applications, if they become cost-effective, will probably not occur until well into the far term. However, some products benefiting from research into molecular manufacturing may be developed in the near term. As initial nanomachining, novel chemistry, and protein engineering (or other biotechnologies) are refined, initial products will likely focus on those that substitute for existing high-cost, lower-efficiency products. Likely candidates for these technologies include a wide variety of sensor applications; tailored biomedical products including diagnostics and therapeutics; extremely capable computing and storage products; and unique, tailored materials (i.e., smart materials using nanoscale sensors, actuators, and perhaps controller elements) for aerospace or similar high-cost/high-capability needs. The current development of MEMS devices may open avenues for incorporating molecular nanotechnological components into widely used systems, such as automotive parts.

As indicated by the large number of U.S. research centers involved in molecular manufacturing and nanotechnology, the United States is a leader in this field. The majority of these centers are in academia and often consist of a few investigators in one or two departments. Identified activity represents a diverse set of basic or applied studies in materials properties. This is vital to providing the building blocks for a technology development. However, this is being done largely without a plan representing an organized, embracing systems-development goal of molecular nanotechnology.

A key observation is that a number of countries are engaged in some level of effort relevant to the foundations of molecular nanotechnology. Although the United States has many groups performing work related to nanotechnology and molecular manufacturing, there are several strong competitors and potential collaborators. Japan has large efforts that are funded individually at a significantly higher rate than their U.S. counterparts and are coordinated by a dedicated national effort. Other nations with strong research centers include China, Denmark, France, Germany, Russia, Sweden, and the United Kingdom.

It is unclear which fabrication method will best succeed--multiple research paths should be left open at the basic and applied research level. Areas that are important to the future of molecular nanotechnology-based advanced manufacturing, and in which successful discoveries could serve other applications in the interim, include the following:

The potential is enormous and could lead to extreme miniaturization in space systems, capabilities in human performance enhancement and medical treatment, as well as ability to manufacture a wide variety of sophisticated products on demand. It might be expected that if sufficient applied science checkpoints are passed, then manufacturers would be motivated to pursue development of applications.

Past experience with translating science into practical engineering provides cautionary examples as well as successes. In principle, civilization can make use of controlled nuclear fusion as an immense source of energy in analogy with nature's application of various fusion reactions to power stars. However, the reality of achieving this has been much more difficult than originally anticipated. Similarly, achieving the manufacture and control of sophisticated molecular nanodevices from current conceptual designs may be more difficult than anticipated.

A fully credible assessment of how far molecular manufacturing will progress in the next two decades is not possible until incremental steps have been undertaken, although tentative indications appear positive. At present, modeling and theoretical underpinnings need to be further developed. Demonstration of assembly, control of chemistry, and practical component creation and integration are important. The laboratory development of several steps should be closely followed for indications that milestones can be expected:

The many laboratory steps needed indicate that a careful decision on development policy, if any, should be made. There are several options: To prevent the possibility of technological surprise, yet not prematurely enact policies that commit funds and valuable resources, a prudent course of action would be to create a working group of biotechnology experts, chemists, computer scientists, electrical engineers, materials scientists, mechanical engineers, and physicists. This group's assessment of a laissez-faire posture versus coordination and cooperation should then be implemented as a basis for a rational policy about support for molecular nanotechnology.

Although there has been much encouraging theoretical and conceptual study of the advanced manufacturing potential of molecular nanotechnology (and panel reports and surveys of expert opinions), a comprehensive, detailed technical assessment by a multidisciplinary, objective expert working group is lacking and should be conducted to determine engineering feasibility. The role of ultrafast phenomena in manufacturing methods and the issue of what applications these could address can be included in conjunction with an assessment of nanoscale technologies (as a secondary focus of how to exploit extreme-scale phenomena).

A positive finding from such an assessment would indicate that cooperation at the basic and applied research level beyond the present situation should be organized. Increased coordination of research funds may improve the cost-effectiveness by reducing redundancy; however, such increased organization should be done in incremental steps so that it does not come at the expense of healthy competition. A negative finding from such an assessment--such as low engineering feasibility; low potential for viable, near-term application; or limited prospects for critical research progress--would strongly indicate that the current levels of funding and structures for basic scientific research in molecular-based nanotechnology is appropriate and that extensive resources should not be dedicated to developing specific pathways.

Contents

Chapter One: Introduction

Chapter Two: Trends and Goals

Chapter Three: Developing Incremental Checkpoints

Chapter Four: National and International Research Efforts

Chapter Five: Conclusions and Recommendation

Appendix: Research Centers in Nanotechnology and Related Areas by Nation

Bibliography

This research in the public interest was supported by RAND, using discretionary funds made possible by the generosity of RAND's donors and the fees earned on client-funded research.

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