[Paleopsych] Economist: (Nanotechnology) Small wonders
Premise Checker
checker at panix.com
Sat Jan 29 16:54:46 UTC 2005
Small wonders
http://www.economist.com/printedition/PrinterFriendly.cfm?Story_ID=3494722
4.12.29
Nanotechnology will give humans greater control of matter at tiny
scales. That is a good thing, says Natasha Loder (interviewed [3]here)
ATOMS are the fundamental building blocks of matter, which means they
are very small indeed. The world at the scale of atoms and molecules
is difficult to describe and hard to imagine. It is so odd that it
even has its own special branch of physics, called quantum mechanics,
to explain the strange things that happen there. If you were to throw
a tennis ball against a brick wall, you might be surprised if the ball
passed cleanly through the wall and sailed out on the other side. Yet
this is the kind of thing that happens at the quantum scale. At very
small scales, the properties of a material, such as colour, magnetism
and the ability to conduct electricity, also change in unexpected
ways.
It is not possible to "see" the atomic world in the normal sense of
the word, because its features are smaller than the wavelength of
visible light (see table 1). But back in 1981, researchers at IBM
designed a probe called the scanning tunnelling microscope (STM),
named after a quantum-mechanical effect it employs. Rather like the
stylus on an old-fashioned record player, it could trace the bumps and
grooves of the nanoscale world. This allowed scientists to "see" atoms
and molecules for the first time. It revealed landscapes as beautiful
and complex as the ridges, troughs and valleys of a Peruvian
mountainside, but at the almost unimaginably small nanometre (nm)
scale.
A nanometre is a billionth of a metre, or roughly the length of ten
hydrogen atoms. Although scientists had thought about tinkering with
things this small as long ago as the late 1950s, they had to wait
until the invention of the STM to make it possible.
Nanotechnology is generally agreed to cover objects measuring from 1
to 100nm, though the definition is somewhat arbitrary. Some people
include things as small as a tenth of a nanometre, which is about the
size of the bond between two carbon atoms. At the other end of the
range, in objects larger than 50nm the laws of classical physics
become increasingly dominant.
There are plenty of materials that simply happen to have features at
the nanoscale--such as stained glass, mayonnaise or cat litter--but do
not qualify for the nanotechnology label. The point about
nanotechnology is that it sets out deliberately to exploit the strange
properties found in these very small worlds.
At the nanoscale, explains George Smith, the amiable head of materials
science at Oxford University, "new, exciting and different" properties
can be found. If you were to start with a grain of sugar, he says, and
chopped it up into ever smaller pieces and simply ended up with a tiny
grain of sugar, that would be no big deal. But as an object gets
smaller, the ratio between its surface area and its volume rises. This
matters because the atoms on the surface of a material are generally
more reactive than those at its centre.
So icing sugar, for instance, dissolves more quickly in water than
does the granulated form. And if silver is turned into very small
particles, it has antimicrobial properties that are not present in the
bulk material. One company exploits this phenomenon by making
nanoparticles of the compound cerium oxide, which in that form are
chemically reactive enough to serve as a catalyst.
In this invisible world, tiny particles of gold melt at temperatures
several hundred degrees lower than a large nugget, and copper, which
is normally a good conductor of electricity, can become resistant in
thin layers in the presence of a magnetic field. Electrons, like that
imaginary tennis ball, can simply jump (or tunnel) from one place to
another, and molecules can attract each other at moderate distances.
This effect allows geckos to walk on the ceiling, using tiny hairs on
the soles of their feet.
But finding novel properties at the nanoscale is only the first step.
The next is to make use of this knowledge. Most usefully, the ability
to make stuff with atomic precision will allow scientists to produce
materials with improved, or new, optical, magnetic, thermal or
electrical properties. And even just understanding the atomic-scale
defects in a material can suggest better ways of making it.
Indeed, entirely new kinds of material are now being developed. For
example, NanoSonic in Blacksburg, Virginia, has created metallic
rubber, which flexes and stretches like rubber but conducts
electricity like a solid metal. General Electric's research centre in
Schenectady in New York state is trying to make flexible ceramics. If
it succeeds, the material could be used for jet-engine parts, allowing
them to run at higher, more efficient temperatures. And several
companies are working on materials that could one day be made into
solar cells in the form of paint.
Because nanotechnology has such broad applications, many people think
that it may turn out to be as important as electricity or plastic. As
this survey will show, nanotechnology will indeed affect every
industry through improvements to existing materials and products, as
well as allowing the creation of entirely new materials. Moreover,
work at the smallest of scales will produce important advances in
areas such as electronics, energy and biomedicine.
From small beginnings
Nanotechnology does not derive from a single scientific discipline.
Although it probably has most in common with materials science, the
properties of atoms and molecules underpin many areas of science, so
the field attracts scientists of different disciplines. Worldwide,
around 20,000 people are estimated to be working in nanotechnology,
but the sector is hard to define. Small-scale work in electronics,
optics and biotechnology may have been relabelled "nanobiotechnology",
"nano-optics" and "nanoelectronics" because nano-anything has become
fashionable.
The "nano" prefix is thought to derive from the Greek noun for dwarf.
Oxford's Mr Smith jokingly offers an alternative explanation: that it
"comes from the verb which means to seek research funding". And
research funding is certainly available by the bucketload. Lux
Research, a nanotechnology consultancy based in New York, estimates
that total spending on nanotechnology research and development by
governments, companies and venture capitalists worldwide was more than
$8.6 billion in 2004, with over half coming from governments. But Lux
predicts that in future years companies are likely to spend more than
governments.
For America, nanotechnology is the largest federally funded science
initiative since the country decided to put a man on the moon. In
2004, the American government spent $1.6 billion on it, well over
twice as much as it did on the Human Genome Project at its peak. In
2005, it is planning to shell out a further $982m. Japan is the next
biggest spender, and other parts of Asia as well as Europe have also
joined the funding race (see chart 2). Perhaps surprisingly, the
contenders include many developing countries, such as India, China,
South Africa and Brazil.
In the six years up to 2003, nanotechnology investment reported by
government organisations increased roughly sevenfold, according to
figures from Mihail Roco, senior adviser for nanotechnology at
America's National Science Foundation. This large amount of funding
has raised expectations that may not be met. Some people worry that
all the nanotechnology start-ups will help to inflate a bubble
reminiscent of the internet one. But there are good reasons to think
that the risk has been exaggerated. Private investors are being much
more cautious than they were during the dotcom boom, and much of the
money that is being spent by governments is going on basic science and
on developing technologies that will not become available for years.
However, a number of existing products have already been improved
through nanotechnology, with more to come in the next few years.
Bandages for burns have been made antimicrobial by the addition of
nanoparticles of silver. Fabrics have been stain- and odour-proofed by
attaching molecules to cotton fibres that create a protective barrier.
Tennis rackets have been strengthened by adding tiny particles that
improve torsion and flex resistance. Other applications include
coatings for the hulls of boats, sunscreen, car parts and
refrigerators. In the longer term nanotechnology may produce much
bigger innovations, such as new kinds of computer memory, improved
medical technology and better energy-production methods such as solar
cells.
The technology's most ardent proponents claim that it will lead to
clean energy, zero-waste manufacturing and cheap space travel, if not
immortality. Its opponents fear that it will bring universal
surveillance and harm the poor, the environment and human health--and
may even destroy the whole planet through self-replicating "grey goo".
This survey will argue that both sides overstate their case, but that
on balance nanotechnology should be welcomed.
More information about the paleopsych
mailing list