Nanotechnology with a cherry on top, please.

[MrFun]

Beyond the basic meaning of nanotechnology, I am ignorant as to the advancements made in applying this technology today, and what is projected for our near future.

I mean, I know this has to deal with production of materials at a molecular level.


But to what extent has nanotechnology been applied already in today's world -- if it has at all?

And are there any reasonable projections made today, as to how nanotechnology will be applied in the near future?


I suppose these questions will be best answered by the tecno-nuts of Apolyton -- and thanks for any information in advance.

[BeBMan]

Haven´t you seen x-files? Soon we all get little implants that control what we do.

[Sandman]

I think they made a face-cream with micro-spheres, or something.

I'm profoundly sceptical of all this nano-nonsense, not least the ludicrous 'grey goo' scenario.

[Starchild]

The revolution's coming boys and girls, better hold onto something....

As usual, the New Scientist has an excellent section devoted to articles from their magazine about nanotechnology. I've pasted one about carbon nanotubes below.

http://www.newscientist.com/hottopics/tech/techindex.jsp?sub=Nanotechnology

Open secret
By Valerie Jamieson
EVERYTHING should look different by now. We should be surrounded by swarms of high-speed computers, each no bigger than a speck of dust. We should be living in houses that snap back into shape after an earthquake or a hurricane. We should be boarding elevators that can carry us into space. If you believed just half of what has been written about carbon nanotubes over the past decade, you might now be feeling a bit disappointed with the impact they have had on today 's world.

But you shouldn 't be. There 's a good chance you now own some nanotubes. Most American cars, not to mention a good number of European ones, contain them. If you 've bought any electronics recently, its components may well have come to you in nanotube-laden packaging. And it won 't be long before you can go camping, gaze up at the stars and thank nanotubes for the electrical power that heated your supper. The revolution has happened you just didn 't notice.

There 's no doubting the potential of nanotubes. They might look like a bit of rolled-up, microscopic chicken wire, but this honeycomb lattice of carbon atoms is the stuff of engineers ' dreams. For instance, their electrical properties mean that nanotubes can be made into metals or semiconductors, depending on how you roll up the sheet of carbon atoms. Roll the carbon the way you roll a cigarette, with the edges touching along their length, and you have a nanotube that acts like a tiny metal wire conducting electricity. Wind the tube askew, like a paper straw, and you have a miniature semiconductor that could replace silicon transistors, the building blocks of chips.

What 's more, nanotubes conduct electricity better than copper, making them a contender for replacing the delicate wires that connect components together inside computer chips. Not only that, but they can carry heat far more efficiently than diamond, one of the best heat conductors around. So if you give processor chips a nanotube coating, you could pack billions of them together into a tiny space with little risk of them burning up.

Perhaps even more impressive are the mechanical properties of these lightweight structures. Nanotubes are over 50 times stronger than steel wire and only a quarter as dense. No matter how hard you squeeze a nanotube, it will bend and buckle without breaking, springing back into shape as soon as you let it go. So who can blame analysts for predicting the emergence of crash-proof cars, nanotube ropes for lassoing space junk, and bulletproof vests lighter than a silk camisole?

Indeed, the strangest thing about the nanotube story is not the hype but the history. Read textbooks, newspapers, magazines, even academic journals, and you 'd think they were a recent invention. But nanotubes may already have been around for more than a century. A US patent granted in 1889 to two British men reveals how to make them using marsh gas better known these days as methane. The method is essentially the same as that used in industrial processes today, and produced "hair-like carbon filaments" for electric lighting. According to the patent, as well as having useful electrical properties, these filaments "may be bent and twisted into various shapes and will spring back to their original form on being released". In the 1960s and 1970s a couple of research groups at the National Carbon company in Parma, Ohio, and the University of Canterbury in Christchurch, New Zealand, respectively also made and characterised carbon nanotubes.

The hype began much later in 1991, after Sumio Iijima and his colleagues created nanotubes at the research laboratory of the electronics multinational NEC in Tsukuba, Japan. Iijima 's "discovery" came just a few years after the surprise finding of buckyballs a new molecular structure for carbon and, perhaps more importantly, the publication of Eric Drexler 's book Engines of Creation. This raised the idea that nanotechnology, making machines on the nanoscale, could provide a solution to virtually any problem you might dream up. By the time Iijima made his announcement, nanotechnology was filtering into academic and government circles as something worth thinking about. Nanotubes were just what we had been waiting for a material to transform the world.

One organisation unimpressed by the 1991 hype was Hyperion Catalysis, a firm based in Cambridge, Massachusetts. Hyperion has been perfecting ways to produce nanotubes by the tonne since 1983. Today, 60 per cent of cars on American roads have fuel lines containing Hyperion 's carbon nanotubes. Their high conductivity dissipates any electric charge that might build up and generate a dangerous spark as the fuel flows past the nylon walls of the fuel line. If you own a Renault Clio or M gane, next time you polish it you 'll also be buffing some of Hyperion 's nanotubes. These are used to make the plastic wing panels so conductive that they can be earthed while the car is sprayed with paint droplets charged up to 20,000 volts. The droplets seek ground instead of floating away, making spray-painting more efficient and less polluting.

At present, Hyperion is the only company that churns out tens of tonnes of "multiwall" nanotubes every year. These consist of between 10 and 12 nested cylinders of carbon, each 10 micrometres long, and cost as little as 2 per gram. Hyperion only sells them incorporated into plastics, but there are plenty of other firms, such as Carbon Nanotechnologies in Houston and Sun Nanotech in Nanchang, China, that sell plain nanotubes by the gram.

Car manufacturers aren 't the only ones who find the conducting qualities of nanotubes useful. They are also prized by the electronics industry. Nanotubes are now incorporated into the carry cases and trays used to transport chips and hard drives. Carry boxes made from nanotube-spiked plastics carry away any charge before it builds up, and their super-smooth surface ensures that tiny tracks aren 't sloughed off the chips whenever they are removed from the packaging.

While the electronics industry is content to use nanotubes to wrap its chips, it would be even more pleased if nanotubes could make the chips in the first place. Every 18 months or so, engineers have been doubling the number of transistors electrical switches composed of carefully arranged layers of semiconductors and conducting electrodes they can cram onto processor chips. For this trend to continue, they will have to carve out ever-tinier transistors from silicon. But within a few years, they will reach the point where the transistors are so small that electrons will be able to tunnel through insulating layers between the components and render the chips useless. To shrink transistors further a radical approach will be needed.

Nanotube transistors connected by nanotube wires might be the answer. But because that would rely on expensive single-walled nanotubes, making this idea a reality is proving hard to do at a reasonable price. A gram of single-wall nanotubes costs 750, around 70 times as much as a gram of gold. The high price is due to the cost of removing any impurities formed during production. The principal means of making nanotubes is by zapping carbon with a laser or by blowing hydrocarbon vapour over a hot metal catalyst (see Diagram). The end result is that most nanotubes tend to be mixed up with impurities such as soot and metal particles. Although you can remove the metal and carbon gunk by washing the nanotubes in acid, it 's expensive and you risk damaging the honeycomb structure and thus the desirable electrical and mechanical properties. IBM is leading the way in getting round these obstacles, but nanotube processors are still a long way off (see "Micro chips").

Using the mechanical properties of nanotubes is proving just as problematic. The idea of a tether reaching into space is looking rather far-fetched the longest nanotube ever made is only 20 centimetres long. And, for the moment at least, embedding nanotubes in materials such as concrete is having the opposite effect to that intended. Instead of adding strength they create weak spots (see "Tangled up").

So, for the moment at least, the nanotube revolution remains focused on plastics spiked with cheap multiwall nanotubes. But don 't scoff it 's still revolutionary. For starters, nanotubes can make plastics conduct better than copper. David Carroll and his colleagues at Clemson University in South Carolina have been adding nanotubes to plastics that already conduct, such as polyaniline (PANI), to boost their performance. "On its own PANI isn 't quite conducting enough to replace copper wires," explains Carroll. "With the addition of nanotubes you could potentially replace all the heavy copper in an aircraft with lightweight plastic wires." Such weight savings would quickly lead to lower fuel consumption.

But some of the most exciting prospects for applications come from Carroll 's work on piezoelectric plastics, materials that produce a voltage when you press or heat them. Last year his group discovered that a polymer widely used in ultrasound sensors, polyvinylidene fluoride (PVDF), becomes three times as sensitive to pressure when nanotubes are sprinkled in. And it doesn 't take much to see an improvement just one nanotube for every 8000 strands of PVDF is enough.

These improvements come about because nanotubes keep the polymer in a stable piezoelectric state. Rolling, pulling, pressing and the other processes used to turn plastics into products normally destroy the molecular structure that makes PVDF a piezoelectric plastic. But Carroll has discovered that the addition of a few nanotubes is enough to hold the piezoelectric arrangement together through thick and thin.

Carroll has grand plans for piezoelectric plastics. "The chemical industry already makes huge vats of PVDF," he says. "It 's just one small step to make nylon fibres." He envisages weaving them into ships ' sails so that they generate electricity as they stiffen in a buffeting wind, enough even to power heating and lighting on board. And, in the future, giant piezopolymer sails might generate electricity for homes.

His group has also added nanotubes into plastic solar cells, and found that they are 50,000 times as efficient at converting sunlight into electricity as other plastic photovoltaic devices. Researchers are keen to make solar cells from plastic because polymers are so cheap and they can be made into huge sheets. When sunlight hits the polymer, it releases electrons and positively charged holes that travel through the material to electrodes, generating a current. But, until now, plastics have made poor photovoltaics because the electrons and holes find it hard to move through the polymer. Instead they meet up and recombine to form light well before they reach the electrodes, giving polymer solar cells an efficiency of only 0.0001 per cent for every million photons that land on the solar cell, just one produces an electric current. They also tend to have a short lifetime, each sheet only working for a couple of hours before oxygen from the atmosphere works its way into the plastic and traps the charge carriers.

But a network of nanotubes running through the polymer gives the electrons and holes a free run towards the electrodes. Carroll 's team has made solar cells that convert 5 per cent of light into electricity and live long enough to be commercially viable. "Some of the devices I made a year ago are still working," he says.

Although the best silicon solar cells are many times more efficient, Carroll predicts strong interest in his material because it could be used to make swathes of electricity-generating solar cells. He believes the market will be driven by an unusual group campers fed up with cooking on gas stoves who will relish the chance to plug in their electrical appliances to their wired-up tent.

OK, so it 's not an earth-shattering technological vision, but it 's no pipe dream either. Nanotubes may not be guiding the space elevator to a holiday destination above the clouds, but the fact remains that they are already worth billions of dollars worldwide. If you were about to cash in your nanotube stock, disappointed by the revolution that never came, you might want to think again.

[Curiosity]

Nanotechnology can have two meanings;

Firstly the manufacture and use of anything one the nanometer scale (or close enough that PR doesn't understand the difference.) This gets used frequently these days, but it's implications are not exactly world-shattering.

Secondly 'molecular nanotechnology', the construction of objects atom-by-atom or molecule-by-molecule. So far this has been used to spell out 'IBM' in individual atoms, and also in some interesting experiments on the wavefunction of electrons. But not for anything you could call practical.

In theory molecular nanotechnology has the potential to transform our lives by eliminating all material need, if when someone constructs a nanite.

However, this is something of an intellectual sleight of hand; this effect is fundamentally provided by the existence of self-replicating machines which can do other useful work. Whether these machines exist at a nano scale or not is pretty irrelevant, except in terms of certain social structures (and maybe the destruction of the earth. ) Also there are issues with power sources and information transmission which make IMO many of the projections for nanotech pretty untenable.

[TCO]

nanotechnology is really closer to lithography than it is to machines. It is more about making tiny wires and the such via chemical means (or even making colloids) than it is about little machines that are the size of bugs. Nanotechnology is a buzzword for science funding.

[MattH]

Some practical applications:
-Blood analasys in your hand,
-Hydrogen generation,
-Drug delivery,
-Computing with nano-transistors &c.,
-Tiny, networked sensors


There is some interesting stuff in MIT's Technology Review.

[MrFun]

Originally posted by Starchild
The revolution's coming boys and girls, better hold onto something....

As usual, the New Scientist has an excellent section devoted to articles from their magazine about nanotechnology. I've pasted one about carbon nanotubes below.

http://www.newscientist.com/hottopics/tech/techindex.jsp?sub=Nanotechnology

Interesting article, Starchild -- I read it, and thought -- wow, cool.

[pchang]

Sci Fi

Go read The Diamond Age by Neal Stephenson - I think the technologies he writes about will be here in 20 years.

[Odin]

Play CtP and you will see the Nanotech stuff I am waiting for.

[MrFun]

Originally posted by Odin
Play CtP and you will see the Nanotech stuff I am waiting for.

CTP was somewhat krappy -- CTP II was very krappy.


Need I say more?

[Kuciwalker]

No.

[Provost Harrison]

Well nanorobotics would be a tremendous strive forward, if you could reproduce them and make them perform specific tasks, perhaps even on a grand scale. Great feats of production and construction become greatly simplified. They could also be used in maintenance of structures, helping to avoid great catastrophes resulting from defects in the structure. Perhaps we can finally have skyscrapers many kilometres high, amongst other probably more important things

[MrFun]

And this will result in another wave of dislocations of previously employed people -- this time in the construction industry, and continued dislocation in other industries, Provost.

[Az]

Originally posted by Provost Harrison
Well nanorobotics would be a tremendous strive forward, if you could reproduce them and make them perform specific tasks, perhaps even on a grand scale. Great feats of production and construction become greatly simplified. They could also be used in maintenance of structures, helping to avoid great catastrophes resulting from defects in the structure. Perhaps we can finally have skyscrapers many kilometres high, amongst other probably more important things

So do you think you'll be able to command them? I don't see how is that possible, besides them following some simple fractal pattern. Now how will you use that fractal pattern in a construction of a building?