The coming of the nano-age
Shaping the world atom by atom
Reading, Writing and Arithmetic. A computer read-head works by passing over layers of very thin films-a few nanometers thick- with differing magnetic properties. As the layers sense the orientation of the magnetic properties, the head's electrical resistance changes. Click here for more photos.
In its broadest definition, "nanotechnology" refers to the
construction and use of structures and devices that range in
size from one to 100 nanometers, a nanometer being one
billionth of a meter. How small is this? A dot one nanometer in
diameter would be approximately 100,000 times smaller than
the diameter of a human hair. A typical virus measures 100
nanometers across. Nanometer-sized features on a computer
chip would be about a thousand times smaller than the
micrometer-sized features on today's chips. This would mean
that all the information stored in the Library of Congress
could be contained in a computer the size of a sugar cube.
By today's standards, that's a supercomputer that can fit in
the palm of your hand.
The arrival of the nano-age will mean that humans can
process matter on a molecular scale; that is, we will be able
to build things atom by atom or molecule by molecule.
When construction takes place at the molecular level, there
is virtually no limit to the shape and size of the objects and
devices you can make. The nano-age is coming, but how
soon this technology arrives will depend upon scientific
"If the dream of molecular-scale matter processing is to
become a reality, it will require research on structures of
nanometer dimensions, and their assembly into complex
functional systems, that is integrated across a broad range
of disciplines," says physicist Daniel Chemla, director of both
the Materials Sciences Division (MSD) and the Advanced
Light Source (ALS) at Berkeley Lab and a leading authority on
the optical and electronic properties of nanoscale materials.
Chemla, like many other leaders in the materials sciences,
advocates changing the paradigm for nanotechnology
research by reducing the time that elapses between the
design, synthesis, measurement and analysis of new
"The ultimate goal is to give the U.S. high-tech industry all
the tools it will need to make new molecules and nano-sized
objects," he says.
Berkeley Lab is well poised to help the nation advance toward
this goal. Its nanoscience program was begun under Chemla's
direction over a decade ago, before the field was recognized
as an important area of research.
"We reoriented research activities at MSD's major
facilities-the National Center for Electron Microscopy and the
Center for X-Ray Optics-to the study of structures of
nanoscale dimensions," Chemla says. "More than two dozen
division investigators were encouraged to expand their
research programs to encompass the field. We also
collaborated with the University of California at Berkeley
Departments of Physics, Chemistry, and Materials Sciences
to recruit many top young scientists, and then provided them
with start-up funds from Berkeley Lab's own Laboratory
Directed Research and Development Program to help them
establish nanoscience programs."
Research at Berkely Lab already encompasses "hard" (inorganic) materials, including
nanocrystals, nanotubes, and lithographically patterned structures, and "soft" (organic
and living) materials, such as polymers, DNA, proteins, and components of living cells.
The nanometer scale is the dimensional regime where hard and soft materials sciences
meet, and Lab researchers already invoke the primary fabrication strategies of both: the
"top-down" approach practiced by solid-state physicists and physical chemists in which
existing structures and objects, such as semiconductors, are made smaller; and the
"bottom-up" approach practiced by chemists and molecular biologists in which atoms and
molecules are connected together to make larger structures and objects.
"For hundreds of millions of years, nature has assembled proteins and other biological
molecules to build a variety of molecular machines," explains Chemla. "The living cell is
the ultimate example of nanoscale matter-processing."
In addition to well-established and strong programs in
materials sciences, Berkeley Lab also hosts three national
user facilities that offer cutting-edge technical capabilities
crucial to effective nanoscale research-the ALS, a
synchrotron radiation source that generates some of the
brightest and most intense x-rays available for scientific
research; the National Center for Electron Microscopy
(NCEM), where researchers can "see" atoms in a crystal
and have achieved subangstrom resolutions of structural details; and the National Energy
Research Scientific Computing Center (NERSC), which is one of the most powerful
unclassified computing resources in the world.
The ability of the microscopes at NCEM to resolve images of objects at the atomic level
speaks for itself, but the ALS gives researchers here an added dynamic. It is not enough
merely to "assemble" nanoscale objects and view them, researchers will also need to
observe them in action to evaluate their performance. This means studying how the
various properties of a given object may evolve over a period of time under changing
conditions. Given the size of the object being studied, these time periods can be
astonishingly short. For example, observing the dynamics of a microchip's electronic
properties may require making measurements within a few billionths of a second.
Observing the same dynamics in a nanometer-sized semiconductor can require time
measurements a million times more brief. This is called the "femtosecond" scale: a
femtosecond is to one second what one second is to 30,000 years. The ALS, which
routinely delivers strobes of x-rays in picosecond pulses (trillionths of a second), has
recently been rigged to yield femtosecond timescale flashes as well.
In addition to experimentation, nanoresearch also requires a substantial amount of
theoretical modeling. For this work, the brute computational power provided by NERSC
becomes a necessity. Theoretical models of hard materials in the past have yielded useful
predictions based on the description of only a few atoms arrayed in a crystal, thanks to
the periodic structure of crystals. Nanosized structures and objects will be an entirely
different story. These constructs might require the modeling of millions of atoms which
may be arranged in a very precise order but without the periodic symmetry of a
conventional crystal. NERSC is one of the few places on the planet with the capabilities
to handle number-crunching of this magnitude.
Berkeley Lab, with its unique combination of national user facilities and strong research
programs in the materials sciences, is an ideal location from which to begin a change in
the nanotechnology research paradigm, as Chemla explains.
"Such a change calls for the kinds of multidisciplinary programs across condensed matter
physics, physical chemistry, organic chemistry, materials sciences, biology, and ultrasmall
device physics already present at Berkeley Lab. Furthermore, at Berkeley Lab, we can
provide researchers with instrumentation and equipment that is too expensive, too
infrequently used, and too demanding of technical staff to be generally available in
university or industrial laboratories. We also offer some of the best characterization
facilities in the country."
The characterization facilities to
which Chemla refers include the
existing Center for X-ray Optics and
its unique electron-beam nanowriter
plus a new, one-of-its-kind
nanofabrication laboratory now in
the planning stage that will provide
state-of-the-art lithography and
Unlike the microlabs of today, where
standardized equipment and
facilities are used to create
standardized devices and structures
for specific functions at
ever-smaller scales, the proposed
nanofabrication laboratory would be
dedicated to the multifunctional
processes and techniques most
directly relevant to chemical and
biological nanosystems. Instead of processing electrons and photons, researchers at the
new nanofabrication laboratory would truly be able to process matter itself.
"Working at the nanometer scale is not simply doing micron-level work with smaller
objects," says Chemla. "Matter at the nanometer scale exhibits very special properties
because of quantum size effects, altered thermodynamics, and modified chemical
reactivity. Under our vision for Berkeley Lab, we would have the facilities and the
scientific staff to meet this much greater challenge."