in the 1980s Xerox sonography clinic

Researchers at AT&T Bell Labs, the University of
California at Berkeley,
S

Like "When will it be achieved?", this is a basic
question with an answer beyond calculation. Here, though, the
answer seems fairly clear. Throughout history, people have worked
to achieve better control of matter, to convince
funding agencies like the National Science Foundation in the
United States and Japan's Ministry of International Trade and
Industryムall have a large influence on research directions,
but so do the researchers working in the labs. They submit
proposals to potential funders (and often spend time on
personally chosen projects, regardless of funding), so their
opinions also shape what happens. Where public money is involved,
politicians' impressions of public opinion can have a huge
influence, and public opinion depends on what all of us think and
say..

Still, researchers play a central role. They tend to work on
what they think is interesting, which depends on what they think
is possible, which depends on the tools they have orムamong
the most creative researchersムon the tools they can see how
to make. Our tools shape how we think: as the saying goes, when
all you have is a hammer, everything looks like a nail. New tools
encourage new thoughts and enable new achievements, and decisions
about tool development will pace advances in nanotechnology. To
understand the challenges ahead, we need to take a look at ideas
about the tools that will be needed.

Why Are Tools So Important?

Throughout history, limited tools have limited achievement.
Leonardo da Vinci's sixteenth century chain drives and ball
bearings were theoretically workable, yet never worked in their
inventor's lifetime. Charles Babbage's nineteenth century
mechanical computer suffered the same fate. The problem? Both
inventors needed precisely machined parts that (though readily
available today) were beyond the manufacturing technology of
their times. Physicist David Miller recounts how a sophisticated
integrated circuit design project at TRW hit similar limits in
the early 1980s: "It all came down to whether a German
company could cool their glass lenses slowly enough to give us
the accuracy we needed. They couldn't."

In the molecular world, tool development again paces progress,
and new tools can bring breathtaking advances. Mark Pearson,
director of molecular biology for Du Pont, has observed this in
action: "When I was a graduate student back in the 1950s, it
was a multiyear problem to determine the molecular structure of a
single protein. We used to say, 'one protein, one career.' Yet
now the time has shrunk from a career to a decade to a
yearムand in optimal cases to a few months." Protein
structures can be mapped atom by atom by studying X-ray
reflections from layers in protein crystals. Pearson observes
that "Characterizing a protein was a career-long endeavor in
part because it was so difficult to get crystals, and just
getting the material was a big constraint. With new technologies,
we can get our hands on the material nowムthat may sound
mundane, but it's a great advance. To the people in the field, it
makes all the difference in the world." Improved tools for
making and studying proteins are of special importance because
proteins are promising building blocks for first-generation
molecular machines.

But Isn't Science About Discoveries,
Not Tools?

Nobel Prizes are more often awarded for discoveries than for
the tools (including instruments and techniques) that made them
possible. If the goal is to spur scientific progress, this is a
shame. This pattern of reward extends throughout science, leading
to a chronic underinvestment in developing new tools. Philip
Abelson, an editor of the journal Science, points out that
the United States suffers from "a lack of support for
development of new instrumentation. At one time, we had a virtual
monopoly in pioneering advances in instrumentation. Now
practically no federal funds are available to universities for
the purpose." It's easier and less risky to squeeze one more
piece of data out of an existing tool than to pioneer the
development of a new one, and it takes less imagination.

But new tools emerge anyway, often from sources in other
fields. The study of protein crystals, for example, can benefit
from new X-ray sources developed by physicists, and techniques
from chemistry can help make new proteins. Because they can't
anticipate tools resulting from innovations in other fields,
scientists and engineers are often too pessimistic about what can
be achieved in their own fields. Nanotechnology will join several
fields, and yield tools useful in many others. We should expect
surprising results.

What Tools Do Researchers Use to Build
Small Devices?

Today's tools for making small-scale structures are of two
kinds: molecular-processing tools and bulk-processing tools. For
decades, chemists and molecular biologists have been using better
and better molecular-processing tools to make and manipulate
precise, molecular structures. These tools are of obvious use.
Physicists, as we will see, have recently developed tools that
can also manipulate molecules.
Combined with techniques from chemistry and molecular biology,
these physicist's tools promise great advances.

Microtechnologists have applied chip-making techniques to the
manufacture of microscopic machines. These technologiesムthe
main approach to miniaturization in recent decadesムcan play
at most a supporting role in the development of nanotechnology.
Despite appearances, it seems that microtechnology cannot be
refined into nanotechnology.

But Isn't Nanotechnology Just Very
Small Microtechnology?

For many years, it was conventional to assume that the road to
very small devices led through smaller and smaller devices: a
top-down path. On this path, progress is measured by
miniaturization: How small a transistor can we build? How small a
motor? How thin a line can we draw on the surface of a crystal?
Miniaturization focuses on scale and has paid off well, spawning
industries ranging from watchmaking to microelectronics.