Gold And The Diamond Age
Diamonds are nature's ultimate suncatcher,
rare gems, the hardest substance known, a symbol of purity and allegedly
a woman's best friend. They are also chemically identical to pencil lead,
the only difference being how the little carbon atoms are lined up. Using
carbon as a kind of Lego set, we should be able to build small machines
to do just about anything and these machines would effectively be built
out of diamond. Once the trick of building these things is known diamond
will be the most common building material, as ubiquitous as plastic and
glass are today. Scientists are starting to refer to this as "The Diamond
Age".
Until
this month, the idea of making little machines out of diamond seemed so
unlikely as to be science fiction for most people. In reality, scientists
have been working on microscopic diamond parts for some time, and the first
diamond machine has now been made. The US Government's Sandia
Laboratories have recently announced the successful creation of the
world's first diamond micromachines. They're still quite large by nanotechnology
standards - the image (courtesy Sandia Labs) on the right is a massive
1/10th of a millimeter tall, or 1/250th of an inch for us old fogeys. The
smallest features are 2um across, which is 0.002mm in metric and really
small in inches.
If you've not guessed what it is yet (The world's smallest slinky? A
comb for eyelashes? A ladder for dust mites?) it's a little pump. Zap it
with some static electricity and the accordion-like bit stretches, sucking
in stuff through the channel on the middle right. Take the electricity
away again, and the accordion collapses, squirting the contents out of
the channel again. It'll do it very fast, and it won't wear out very quickly.
What's more, diamond will coexist happily with the silicon used in silicon
chips, and the insides of our own bodies. This could make for some very
interesting medical equipment, capable of delivering precise doses of drugs
to afflicted organs, and staying inside the body indefinitely. Motors,
sensors and other cunning artifacts are on the drawing board.
The
Tiny Golden Globe
While we might be able to make diamond from carbon, gold is just gold any
way you look at it. What two chemical engineers in the University of Texas
saw in gold was a factory in miniature. They found a way of making microscopic
blobs of gold - clusters of a couple of hundred atoms at most - attract
silicon. Then they cranked up the pressure so that the blobs of gold ripped
silicon from a solution and dissolved them. When the pressure is
cranked up further, the blobs spat the silicon out as fine wires, like
silk out of a spider's butt only far, far smaller. The image on the left
(50nm is 0.000005mm) shows some of these gold blobs stuck to the surface
of minuscule silica balls; even scientists have to stick them down to something
to take a photograph.
The tiny, silicon wires that Dr.
Brian Korgel and Dr. Keith Johnston produced are only 4nm long. As
the very latest features on the highest quality microchips are 100nm long,
the wires are too small to use today. But as science plods on, these tiny
wires will be needed to make the next generation of lasers, sensors and
computer screens. The manufacture of the wires is very sophisticated, involving
a pressure of 5,000 pounds per square inch and temperatures of up to 500
degrees Celsius, using strange properties of materials called supercritical
fluids. Supercritical fluids are also used to make fat-free chips rather
than silicon chips, but under somewhat less extreme conditions. Their next
trick is to make plugs so that they can connect the wires into circuits
and minuscule electronic devices.
The Zyvex Production Line
Zyvex
is a bona fide company in the US that is dedicated to producing nanomachines.
While the actual nanomachines are still beyond our capacity to make at
this point (although Zyvex are of course working on it) there are still
things that can be done. Once we've made these tiny machines, we'll need
ways to pick them up, put them together and place them safely in storage.
To this end, Zyvex are making the nanoscale equivalent of production line
tools. So far they've shown things like 0.1mm diameter turntables (left),
moving platforms and tweezers (right) a mere 0.5 mm long. While at the
leading edge of what our current technology is today, these are the nanotech
equivalent of forklift trucks, gantry cranes and palettes.
Zyvex
are also working on miniature pegboard (left) and on using long tubes of
carbon atoms called nanotubes as a kind of conductive rope. A special robot
called "The Zybot" as been developed by them that can move these tiny little
constructions around with great agility. They have also proposed a couple
of handy little molecules, one of which is represented by that cluster
of balls on the right, that are large enough to handle and stick together;
much like the Lego assembly trick mentioned earlier. This is all being
done by some of the major players in the field, some of which I have had
the honour of working with.
Back
At The IBM Corral
IBM - you may have heard of them - announced on the 2nd February that they
had demonstrated the first atomic-scale electronic circuit. Looking more
like a corral than a circuit (and called a "quantum corral" by the boffins),
it controls electricity in a startling new way. The image on the left is
from a real circuit 20 nanometers (20 millionths of a millimetre) in diameter
scanned with a special electronic microscope called an STM. The ring of
points are individual atoms of cobalt. The lump in the middle on the right
side is another atom of cobalt, but the lump on the left is an echo of
the electrical fields caused by the atom on the right. Instead of conducting
electricity down a wire, it can now be bounced around like echoes in a
dome. This opens yet another way for a whole new field of electronics and
electrical devices using minuscule quantities of power and being far smaller
than conventional computer chips. Our small future is getting closer.
Back to the Launchpad Main Page