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Nanotechnology Basics: For Students and Other Learners

“The principles of physics, as far as I can see, do not speak against
the possibility of maneuvering things atom by atom. It is not an attempt to
violate any laws; it is something, in principle, that can be done; but in
practice, it has not been done because we are too big.”

Richard Feynman, Nobel Prize winner in physics

  1. Common Questions on
    Nanotechnology
  2. CRN Student
    Research Project


  3. Nanotechnology Education Group


  4. Student Pugwash Nanotech Page
  5. More! More! More!


What is nanotechnology all about?
Image

Nanotechnology
is the engineering of tiny machines — the projected ability to build things from
the bottom up
inside
personal nanofactories
(PNs), using techniques and tools

being developed today
to make complete, highly advanced products.
Ultimately, nanotechnology will enable control of matter at the nanometer scale,
using mechanochemistry. Shortly after this
envisioned molecular machinery is created, it will result in
a
manufacturing revolution,
probably causing severe disruption. It also has serious economic, social, environmental, and military
implications.

A nanometer is one billionth of a meter, roughly the
width of three or four atoms. The average human hair is about 25,000 nanometers
wide.

You can see a longer explanation
here. And to check out
more of those tiny machines,

click here
.

What’s a personal nanofactory?

It’s a proposed new appliance, something that might sit on a
countertop in your home.
To build a personal nanofactory
(PN), you
need to start with a working fabricator, a

nanoscale
device that can combine individual molecules into useful shapes. A
fabricator could build a very small nanofactory, which then could build another
one twice as big, and so on. Within a period of weeks, you have a tabletop
model.





Click to
enlarge

Artwork by John Burch,

Lizard Fire Studios
(3D Animation, Game Development)

Products made by a
PN will be assembled from nanoblocks, which will be fabricated within
the nanofactory. Computer aided design (CAD) programs will make it possible to
create state-of-the-art products simply by specifying a pattern of predesigned
nanoblocks. The question of when we will see a flood of
nano-built products
boils down to the question of how quickly the
first fabricator can
be designed and built.

MOVIE TIME: A short film
called Productive Nanosystems: from Molecules to Superproducts depicts an
animated view of a nanofactory and demonstrates key steps in the sample process
that converts basic molecules into a billion-CPU laptop computer.
The 4-minute streaming video is online
here.

What could nanofactories produce?


How does ‘mechanochemistry’ work?

It’s a bit like enzymes (if you know your
chemistry): you fix onto a
molecule or two, then twist or pull or push in a precise way until a chemical
reaction happens right where you want it. This happens in a vacuum, so you don’t
have water molecules bumping around. It’s a lot more controllable that way.

So, if you want
to add an atom to a surface, you start with that atom bound to a molecule called
a “tool tip” at the end of a mechanical manipulator. You move the atom to the
point where you want it to end up. You move the atom
next to the surface, and make sure that it has a weaker bond to the tool tip
than to the surface. When you bring them close enough, the bond will transfer.
This is ordinary chemistry: an atom moving from one molecule to another when
they come close enough to each other, and when the movement is energetically
favorable. What’s different about mechanochemistry is that the tool tip molecule
can be positioned by direct computer control, so you can do this one reaction at
a wide variety of sites on the surface. Just a few reactions give you a lot of
flexibility in what you make.

MECHANOSYNTHETIC
REACTIONS Based on quantum chemistry by Walch and Merkle
[Nanotechnology, 9, 285 (1998)], to deposit carbon, a device moves a
vinylidenecarbene along a barrier-free path to bond to a diamond (100) surface
dimer, twists 90° to break a pi bond, and then pulls to cleave the remaining
sigma bond.


Why do some scientists
dismiss this stuff as science
fiction?

The whole concept of advanced
nanotechnology — molecular manufacturing (MM) — is so complex and unfamiliar, and so staggering in its
implications, that a few scientists, engineers, and other pundits have flatly
declared it to be impossible. The debate is further confused by
science-fictional hype and media misconceptions.

It should be noted that none of those who
dismiss MM are experts in the field. They may work in chemistry, biotechnology,
or other nanoscale sciences or technologies, but are not sufficiently familiar
with MM theory to critique it meaningfully.

Many of the objections, including those of
the late Richard Smalley, do not address the actual published proposals for
MM.
The rest are unfounded and incorrect assertions, contradicted by detailed
calculations based on the relevant physical laws.

Is nanotechnology
bad or good?

Nanotechnology offers great potential for
benefit to humankind,
and also brings severe
dangers
. While it is appropriate to examine carefully the risks and possible
toxicity of nanoparticles and other products of nanoscale technology, the
greatest hazards are posed by malicious or unwise use of molecular manufacturing. CRN’s focus is on
designing and promoting mechanisms for
safe development and
effective
administration
of MM.

If MM is so dangerous, why not just
completely ban all research and
development?

Viewed with pessimism, molecular
manufacturing could appear
far too risky to be allowed to develop to anywhere near its full potential.
However, a naive approach to limiting R&D, such as

relinquishment
, is flawed for at least two reasons. First, it will almost
certainly be impossible to prevent the development of MM somewhere in the world.
China, Japan, and other Asian nations have thriving nanotechnology programs, and
the rapid advance of enabling technologies such as biotechnology, MEMS, and
scanning-probe microscopy ensures that R&D efforts will be far easier in the
near future than they are today. Second, MM will provide
benefits that are
simply too good to pass up, including environmental repair; clean, cheap, and
efficient manufacturing; medical breakthroughs; immensely powerful computers;
and easier access to space.

What about “grey goo”?

The dangers of self-replicating
nanobots — the so-called grey goo — have been widely discussed, and it is generally
perceived that molecular manufacturing is uncomfortably close to grey goo.
However, the proposed production system
that CRN
supports does not involve free-floating assemblers or nanobots, but much larger
factories with all the nanoscale machinery fastened down and inert without
external control. As far as we know, a self-replicating mechanochemical nanobot
is not excluded by the laws of physics, but such a thing would be extremely
difficult to design and build even with a full molecular manufacturing
capability. Fiction like Michael Crichton’s Prey might be good
entertainment, but it’s not very good science.

How soon will
molecular manufacturing be developed?

Based on our studies, CRN believes that

molecular
manufacturing
could be successfully developed within the next ten years, and almost
certainly will be developed within twenty years. For more, see our

Timeline page.

Shouldn’t we be working on
current problems like poverty, pollution, and
stopping terrorism, instead of putting money into these far future
technologies?

We should do both! Development and
application of molecular manufacturing clearly can have a positive impact on
solving many of today’s most urgent problems. But it’s equally clear than MM
can exacerbate many of society’s ills. Knowing that it may be developed within
the next decade or two (which is not “far future”), makes preparation for
MM an
urgent priority.


More! More! More!

Nanotechnology: Get REAL!
– An online PowerPoint
presentation

Nano Simulation
A way to visualize what is meant by molecular manufacturing

Nanotechnology on an Upward
Slope

– An online PowerPoint
presentation

CRN’s
Responsible Nanotechnology Blog

– Stay up to date every day


Must-See Nanofactory Movie – Four minutes of fantastic future
tech


CRN-talk
– Join the conversation!

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