Society is increasingly dependent on the quality, reliability, and security
of the software governing the systems and products we use, from telephones
system and military systems to our automobiles and even washing machines.
In Update 11 Norm Hardy examined the prospects for better security
against viruses and other outside attacks through the use of secure operating
systems. One can also ask the more general question of how software can
be made better in quality and reliability.
In the case of most products, improvements are made gradually: copies of
the same item are used by many customers, who make their views known by
refusing to buy again, complaining, or even returning the product in disgust.
This process works for consumer software which is sold in many copies. But
much software of importance is produced and used within a company or organization:
how could the producers of such software take advantage of the process of
gradual improvement based on customer reaction?
If software could be written in functional chunks, and fit together in a
modular fashion to perform different tasks, these chunks could be bought
and sold. While modularity is increasing, we don't yet see a vigorous software
components market. The question of why not is being pursued by the the Agorics
Project team at George Mason University's Center for the Study of Market
Processes. Here are some excerpts from their proposal to study the problem:
"A vigorous software components industry would mean enormous benefits
to both producers and consumers of software--on this point actors in the
software industry broadly agree. Widespread reuse of software components
would mean greater productivity, more rapid innovation and improvements
in quality, lower cost, more timely product development and delivery, and
greater ability to cope with complexity.
"But such an industry is frustratingly slow in developing. Far from
using standard, well-established building blocks in assembling their software
systems, today's software engineers spend a tremendous amount of time and
creativity reinventing and rebuilding what has been built before--often
many times over.
"To be sure, there has been progress: The development of object-oriented
technologies especially appears to be a crucial step in enabling the development
of a software component industry. In addition there are improvements in
network connectivity and database technologies which should allow for effective
communication in component markets.
"But extensive production and marketing of reusable software components
have not developed. Why not? What further changes need to take place to
catalyze the development of a vigorous software component industry? The
purpose of the study proposed here is to find out answers to these questions.
"The study will pay special attention to the interrelationships between
technological developments, on the one hand, and economic, legal, and institutional
factors on the other. While we are very interested in and closely follow
the technological developments, as economists we expect to make few specifically
technological suggestions in this study. Rather we will focus on background,
analysis, and projections of the non-technological issues which will shape
the success of technological developments.
"This overview should be a valuable resource to all who would participate
in the development of the software components industry. Those approaching
it from the technological standpoint will gain insight into the economic
and cultural factors that constrain the success chances of new technologies,
and those approaching it from the business standpoint will gain insight
into the technical possibilities it might be profitable to support."
The project leader is Prof. Don Lavoie, ably assisted by advanced graduate
students Howard Baetjer, Bill Tulloh, and Kevin Lacobie, all of whom are
conversant with both economics and programming. Funders wishing to participate
in the project can contact CSMP at 703-993-1142; fax 703-993-1133.
Special thanks go to Chris Rodgers for two years of highly competent Foresight
work; she leaves us now to continue a career in the theatre.
Special thanks are due to Fred Stitt, who served as publisher of Foresight
Update for its first four years. His assistance during these early
years has been greatly appreciated.
Thanks also to:
Stewart Cobb for taking on the main leadership position within the
new Molecular Manufacturing Shortcut Group within the National Space Society.
BC Crandall for his arduous work on completing the Foresight conference
proceedings (MIT Press, late 1991).
James Lewis for his earlier (also arduous) work at the start of the
proceedings project.
Marc Stiegler, Ray Alden, and Jim Bennett for founding IMM; Lynne
Morrill for directing it; Eric Dean Tribble for recruiting Miss Morrill.
ERATO researcher Christopher Jones and Kiyomi Hutchings for Japanese
translation help.
Ralph Merkle and Leonard Zubkoff for computer time and help.
Gayle Pergamit for screening job candidates.
Ted Kaehler for organizing the successful nanotechnology discussion
group within CPSR, and much other help.
Mark Hopkins, Margaret Jordan, Duncan Forbes, and many others for
support within NSS.
Thanks to the following for sending technical articles and media coverage:
Joe Bonaventura, Jim Conyngham, Doug Denholm, Robert Edberg, S.F. Elton,
Jerry Fass, D.J. Fears, Joseph Fine, Dave Forrest, W.C. Gaines, A.P. Hald,
William Hale, G. Houston, Stan Hutchings, Christopher Jones, Marie-Louise
Kagan, Cherie Kushner, Henry Lahore, Tom McKendree, Bob Newbell, John Papiewski,
John Primiani, E.A. Reitman, Naomi Reynolds, Jeffrey Soreff, Alvin Steinberg,
Ralph Tookey, and Jack Veach.
From our "Thanks" column it's clear
that many readers are already sending in articles, both technical and nontechnical.
We'd like to make this more systematic for the technical articles, with
volunteers agreeing to monitor specific journals. If you routinely look
at one or more of the following and are willing to send us copies of relevant
articles, please contact us: Angewandt Chemie, JACS,
J. Appl. Phys., Appl. Phys Lett., Protein
Engineering, J. Computational Chemistry, J. Molecular
Electronics. As always, articles from other publications are welcome.
We already monitor Science, Nature, and Science
News. We'd also appreciate help from Japan in identifying relevant
journals and obtaining abstracts in English of key articles.
Someone with routine access to NEXIS could help us by running periodic searches
on the word nanotechnology.
Layout help is needed on the Macintosh, using PageMaker software.
We are in need of the following materials and help: a fax machine and a
laser printer for the Macintosh. Office space in the Palo Alto area is needed
as well. Volunteers with legal or fundraising experience are needed. Note
that donations of equipment or funds are tax-deductible in the U.S. as charitable
contributions.
If you or your company can help with any of the above, please call us at
415-324-2490.
Nanoelectronics: Early Results from the Top-Down
Approach
Book Review by Tihamer Toth-Fejel
Nanostructure Physics and Fabrication: Proceedings of the International
Conference, ed. Mark A. Reed and Wiley P. Kirk, Academic Press, 1989,
$64.50.
For decades the goal in electronics has been to make devices smaller, with
the benefits of greater speed and lower cost. This progression--smaller,
faster, cheaper--can be plotted on a graph to give a smooth curve: so smooth
that it's tempting to assume that the process will simply continue as it
has until the ultimate limits are reached.
The techniques now used in micron-and submicron-scale electronics have been
described by Drexler as the top-down approach to miniaturization:
bits and pieces of a larger structure are removed until the desired structure
remains--like sculpting. Despite the stunning (and continuing) successes
of this approach, it breaks down when molecular precision is desired. Because
the starting material doesn't have each atom in a desired location, the
final product doesn't either.
To get an object with each atom where we want it, the object has to be constructed
that way from scratch: this is called the bottom-up approach, described
in Drexler's book Engines
of Creation. In a new technical book, due out in spring1992, he
explains how positional chemistry will lead to a broad ability to perform
molecular manufacturing. Products would of course include electronics.
Given this theoretical advantage, why are so many (including the editors
of Nanostructure Physics) still pursuing the top-down path?
Simply put, the top-down approach has not yet reached its limits, and improved
devices can be made much faster this way than by figuring out how to implement
the bottom-up approach.
While STMs can write the world's smallest advertisement--the IBM logo using
35 xenon atoms--no useful structures have yet been built. Further, before
commercially-viable quantities of electronics can be built with molecular
precision, we will need a highly-parallel system, using molecular machines
for molecular manufacturing.
Top-down researchers are intrigued nonetheless. Yale's Mark Reed feels that
in order for nanostructures to succeed commercially, they must
be built bottom-up, because the error rate from the top-down approach is
too expensive. Wiley Kirk of Texas A&M believes that studying simple
structures (which are all we can build using the top-down approach) is more
rewarding at this point, because their lower complexity makes it possible
to understand the fundamental processes at work. He also believes that the
two points of view--top-down and bottom-up--will merge in ten to twenty
years.
Fortunately, devices constructed with existing top-down techniques can give
scientific data that are relevant for all molecular-scale electronics, regardless
of how they're made; that's why Nanostructure Physics and Fabrication
is of interest even to those looking at the long term. It is, however, a
difficult book: If you are not in the field, even if you've studied quantum
mechanics and graduate-level solid state physics, you will probably find
most of it too technical.
For those wishing a quick introduction to some of the concepts involved,
I highly recommend R. Reed's article in Byte (May 1989) on
"The Quantum Transistor" and Mark A. Clarkson's "The Quest
for the Molecular Computer" in the same issue. Clarkson's article is
especially relevent; it references Engines and leans toward
the narrow definition of nanotechnology. Another good introduction is Claude
Weisbuch's chapter in Semiconductors and Semimetals, Volume
24, edited by Raymond Dingle. Academic Press will soon release an expanded
version of this chapter as a textbook (title unknown at this time).
The serious reader can dig into Nanostructure Physics and Fabrication.
Most of the book consists of papers delivered at a symposium held at College
Station, Texas, from March 13-15, 1989. It is a scientific study of nanostructures,
mostly with respect to nanoelectronics, with many papers full of quantum-mechanical
equations. Realizing the difficulty of their subject, the editors did not
simply collect the papers from the symposium. The book starts with an overview
and background, continuing with three introductory papers to introduce readers
to the topic. Because of the electrical engineering emphasis, the most interesting
consequence of this important work is that it shows how quantum-electronic
nanodevices can work faster than those implemented in rod logic.
Though quantum mechanics has been around since 1923, it is only recently
that electrons have been observed demonstrating nonclassical transport behavior
in electronic components. This behavior was only observable in limited,
low-temperature and complex many-bodied systems, but now nanostructures
make it possible to observe "large scale" quantum effects. For
example:
Large quantum tunneling effects can be observed in resonant tunneling
structures, showing that artificially-induced quantum states could show
nonclassical electron transport.
The fabrication of semiconductor quantum wires, so that quantum transport
becomes dominant, makes the wave nature of the electron very apparent, leading
to electron waveguides similar to their microwave counterparts (though six
orders of magnitude smaller).
When the number of carriers becomes countably small, the quantized
conductance of ballistic point contacts opens up an entire area of quantum
interference-effect devices.
The rest of the book contains numerous technical papers on lateral periodicity
and confinement, quantum devices and transistors, equilibrium and nonequilibrium
response in nanoelectronic structures, quantum wires and ballistic point
contacts, and related structures and phenomena.
A symposium on similar topics, "Nanostructures and Mesoscopic Systems,"
was held in Santa Fe on May 20-24, 1991. Leading researchers from MIT, Yale,
U.C. Santa Barbara, IBM Watson, Bell Labs, and Texas Instruments presented
their results.
Tihamer Toth-Fejel is a Research Engineer at the Industrial Technology
Institute (Ann Arbor, Michigan) and did his master's thesis on self-replicating
automata. He can be reached at 313-769-4248 or ttf@iti.org.
