Ask the guy studying nanotechnology

[AllWalker]

At the request of the chat room, I am starting this thread. Some background - I am currently at the University of New South Wales and am in my 4th and final year in a Bachelor of Science degree, with honours in nanotechnology.

Nanotechnology is a field that crosses between physics, chemistry, materials science and biology. Throughout my degree I have studied these things roughly equally, up until last year when physics and biology were less emphasised, and this year is almost entirely chemistry (by my choice). Or, to put it another way...

Nanotechnology is the science of manipulating things where at least one of the scales is less than 100 nanometres. A wanky definition, but apt enough. Better put into layman's terms as working with molecules to build stuff.

My thesis topic is called "Biocompatible Sensors based on Quantum Dots". This makes sense if you break it down...
Biocompaible = wont kill you if you are exposed to it
Sensors = detects stuff
Quantum Dots = microscopic particles of semiconductors. Have weird physical properties somewhere in between classical and quantum physics. Among these physical properties is high fluorescence - basically, they glow at particular colours when exposed to energy.

In other words, I am working on tiny glowy particles that will detect stuff but not kill you.

Any questions?

[Exy]

Any questions?

I know less than zero so just to start out with, what examples of nanotechnology do people outside of labs run into? Are there consumer products made possible through nanotechnology research? Medical equipment? Military-grade weapons? What real-world uses has it been put to?

[What Exit?]

Can you talk about how close we are to nanotech room temp superconductors? Can they make long carbon nanotubes threads and ribbons yet?

Where do you see the real material breakthroughs in the near future?

[ivan astikov]

When nano-bio-engineering hits its stride, will that be time for the unwashed masses to start worrying? How likely are the general public to ever get access to that sort of treatment?

[The Logos]

As one of those posters who called for this OP in chat, thank you Allwalker for opening this discussion. Nanotechnology really is an endlessly fascinating subject, and a field which I believe will open very significant technological and economic possibilities. I look forward to reading others' questions and your answers. A few questions which come to my mind:

What Exit? raised the question of carbon nanotubes and the weaving techniques to manufacture nanotube threads and ribbons. In particular, I'm interested in what you believe the time scale is for when the technology might be ripe to construct a space elevator as envisioned by Bradley Edwards.

A question I initially raised in chat pertained to the Casimir Effect. In particular, constrained by the energy densities involved with the Effect and using this as a limiting condition, I'm wondering about the prospects for an energetically self-sufficient nanobot based on extracting this vacuum energy?

Is your discipline sufficiently asligned with quantum computation to have an opinion on the future of quantum computers?

What other sort of quantum oddities are thought to be exploitable as the basis for technologies in nanotech applications?

What do you perceive to be the most important short and long-term possibilities for nanotechnology in general?

[AllWalker]

Any questions?

I know less than zero so just to start out with, what examples of nanotechnology do people outside of labs run into? Are there consumer products made possible through nanotechnology research? Medical equipment? Military-grade weapons? What real-world uses has it been put to?

Ah, an easy question to start off with. There are endless applications already out there, but I will constrain myself to those I am more familiar with.

One of the more popular examples of nanotechnology products were those invisible sunscreens that came out recently. These have the same UV protection as zinc (the thick, white creamy sort of sunscreens) while being transparent. They did this with the simplest of nanotechnology applications - they took zinc oxide, shrunk the particles down to the nanoscale, an dmixed it in. At these sizes the particles absorb UV light but not visible light.

There are clothes which don't get dirty. The military has leapt on this one. As far as I can tell the surface of the fabric incorporates what I call Lotus technology - ie, the surface is similar to that of a Lotus leaf. Due to the rough structure (on a molecular level) of the surface, water does not stick to the material and simply rolls off, carrying dirt with it.

You know those sunglasses which automatically darken when exposed to more light? Silver nanoparticles.

Home pregnancy tests and blood glucose measuring kits can also be considered nanotechnology, at a stretch. These incorporate the use of enzymes and antibodies fixed to a surface which binds with specific chemicals, which then somehow relay the information to the user. In the case of preg tests, this is done using antibodies carrying dyes. In the case of glucose sensors, the sensor breaks down the glucose to provide an electrical current which is measured.

There are early stage "labs on chips", which are portable devices which you can inject a sample (water, soil or blood) into, and will then tell you if certain pathogens are present. These devices are inflexible, limited in the number of pathogens they can identify and are a little too sensitive to the conditions they are used in to be adopted, but under lab conditions they work perfectly.

There are certainly others, but these are the only ones I can think of right now.

[AllWalker]

Can you talk about how close we are to nanotech room temp superconductors? Can they make long carbon nanotubes threads and ribbons yet?

Where do you see the real material breakthroughs in the near future?

RT superconductors? We are a long, long way off those. Apart from a few radical theories, no one is even sure how to approach the problem - certainly the current techniques fail to get superconduction outside the lab. Antarctica is too hot for them.

As for carbon nanotubes there are a lot of neat things we can do with them. It is child's play, for example, to grow tubes within tubes. We can control the length of them down to the nanometre. However, they are highly rigid, and I think the record length for one is 1 millimetre. As far as I know we can only grow them as bristles.

But then, there may have been some very recent work that I have not heard about.

For those who are wondering what I am talking about, carbon nanotubes are a different way for carbon atoms to be arranged. Sort of like how graphite and diamond, despite both being essentially pure carbon, have very different properties. Carbon nanotubes look a bit like chicken wire mesh rolled into a tube, only it's a tube so small atoms can't fit down the middle of it. It is as strong as diamond but highly conductive. Very interesting material.

[AllWalker]

When nano-bio-engineering hits its stride, will that be time for the unwashed masses to start worrying? How likely are the general public to ever get access to that sort of treatment?

Nano-bio-engineering is a broad term. Really, it could apply to most modern implants and other devices implanted in the body.

As with everything else in life, the newer treatments start off inaccessible but eventually become cheaper and cheaper. The first big revolution I see is targeted drug delivery. Drugs have so many side effects because we expose our entire systems to them. Suppose there is a cancer treatment drug - the patient swallows it or has it injected, it traverses the bloodstream interacting with whatever it can get it's dentates on, whether cancer or not. These limits the types of drugs that can be used as causes most of the side effects.

Now, imagine a drug which is encapsulated in a protective shell. It navigates the bloodstream harmlessly, finds the cancer cell, and releases the drug at the site it is needed. It would require a fraction of a percentage of the dosage and eliminate side effects.

It sounds like science fiction but the principle is sound. I expct there will be trials within the next few years, if there aren't any already. And since it would save enormous amounts of money and lives, I would expect this to be implemented rapidly across the world shortly after its approval.

But then, there will be all kinds of expensive, unaffordable treatments. Liver boosting, artificial immune systems, nerve regeneration. How plausible these are I don't know, but expect somethings similar to arise over the next couple of decades.

[AllWalker]

As one of those posters who called for this OP in chat, thank you Allwalker for opening this discussion. Nanotechnology really is an endlessly fascinating subject, and a field which I believe will open very significant technological and economic possibilities. I look forward to reading others' questions and your answers. A few questions which come to my mind:

I'm glad for any opportunity to appear smart, so thank you for this chance.

What Exit? raised the question of carbon nanotubes and the weaving techniques to manufacture nanotube threads and ribbons. In particular, I'm interested in what you believe the time scale is for when the technology might be ripe to construct a space elevator as envisioned by Bradley Edwards.

As I said above, the record for carbon nanotubes are 1 millimetre. While they are the best candidates we have for space elevators, they are clearly a long way off. But how knows? A paradigm-shifting techniques may be discovered tomorrow. But I suspect that even with the science fully understood, such a project would rival the Apollo program. It would take decades dedicated towards the project, and with more traditional avenues in to space becoming cheaper and cheaper I would not hold my breath. Once the need for traffic between Earth and orbit increases enough to make it justified, then we would see something like this attempted.

But only if we worked out how.

A question I initially raised in chat pertained to the Casimir Effect. In particular, constrained by the energy densities involved with the Effect and using this as a limiting condition, I'm wondering about the prospects for an energetically self-sufficient nanobot based on extracting this vacuum energy?

Developing nanomachines which self contained power units is a goal only a few are pursuing. Mainly because it is believed to be beyond us at this stage. But like anything in science if someone were to show that it was at least plausible we would see a flurry of activity in the field. As it is, though, most of the attempts to power it are based on either biochemical energy (in biomimicry of bacteria) or solar power (in biomimicry of cyanobacteria).

However, the Casimir Effect has a few limitations:
1) It needs to be in a vacuum. Vacuums are annoying to set up, and performing work in them is hard.
2) Constructing nanoplates and attaching them to a nanomachine in such a way as to use the force between them to create work, under vacuum, would be hard. Not impossible and if you showed that it would work people would do it, but it is an enormous limitation
3) I'm not sure the work generated would be sufficient

However, I don't really know. What I do know is somewhere, somehow, someone is probably looking into the matter. If they succeed they will be rich and famous. Wish them luck.

Is your discipline sufficiently asligned with quantum computation to have an opinion on the future of quantum computers?

My discipline? No. But I have studied quantum computing at an undergraduate level, just enough to know the basics. Plus, my uni is famous for its work in the field and I have been taught several times by a couple of the leading researchers.

The current approaches to quantum computing are the most viable at the moment. Assuming there are no revolutionary new ideas in the near future, my prediction regarding QCs are reminiscent of that of Professor Frink's:

I predict that within 100 years, computers will be twice as powerful, ten thousand times larger, and so expensive that only the five richest kings of Europe will own them.

Imagine that the computer you are sitting in front of had to be assembled out of a block of ultrapure material (and I mean no impurities, or as close to that as physically possible) to which specific impurities are added atom by atom. Each atom must be placed in a specific spot, with any errors proving fatal.

Now, we can do that sort of thing, in principle. The technology to pick up, move, and place where you want them individual atoms is actually about 20 years old. But to build a quantum computer, assuming you even knew how, would require a skilled operator using expensive equipment something like 6 months to 2 years to build just one. So QCs might come into existence, but only the 5 richest kings of Europe will afford them.

Of course, today most computer chips are designed by computers. Once we have 1 QC, we might be able to use it to design a simpler, better computer, or find a way to make the process easier. Who knows?

What other sort of quantum oddities are thought to be exploitable as the basis for technologies in nanotech applications?

Perhaps quantum entanglement, as a means to coordinate elements in a nanosystem or as communicators. Most of my quantum physics comes from 2nd Year undergrad courses and books like A Brief History of Time, so I'm not the best person to ask.

What do you perceive to be the most important short and long-term possibilities for nanotechnology in general?

Technical goals should, and do, include a focus on the rising importance of biomedical sciences. The things I talked about like artificial immune systems should be next on the research table, once we develop and perfect what is already on the research table. Those are short term.

Long term include actual machines. What we have are things that are the equivalent of hammers and hinges, while what we should be aspiring to is the electric motor. Nanomachines that can act under their own power, specially designed tools to remove cholesterol from our blood and nitrous oxides from the air. Smart materials - we already have things which can change opacity and colour at the push of a button, but what we need are things which can change hardness, conductivity, shape, all manner of properties.

But there are non-technical goals, too. Nanotechnology has the potential to be seen the same way as radiation - overwhelmingly useful, but a few problems, so is viewed by society at large as undesirable. Educating the masses about nanotechnology is part of a solution. I would like to see some Hollywood blockbusters where nanotechnology is applied accurately. No self replicating, grey goo causing bullshit. Real stuff, because the real stuff is awesome enough.

But another approach is to intergrate our everyday lives with nanotechnology, so that any thought of rejecting it seems ludicrous. There are many projects out there that would help - paint and windows which generate electricity from sunlight, walls, which are grafitti-proof, anti-mould coffe mugs - the technology is there, we just need to make sure people become aware they can't live without it.

[Walker in Eternity]

AllWalker, hope you don't mind me chipping in a little. What do you intend to do once you graduate? There are lots of research postions out there in Nanotechnology at present.

Nanotechnology is also key in the field of organic electronics, i.e. using polymers instead of silicon. I am a PhD student at a UK University and am researching organic photovoltaics, many of which use blends of polymers with nanoparticles such as fullerene. CNTs have also been used and some research is being done on using quantum dots in photovoltaics (not here though).

My colleagues are working in a number of areas, such as thin film transistors, plastic memory devices and biosensors, most if not all of them use nanoparticles in some form or other as these are key to the success of the projects.

One of the most intersting thing about nanoparticles is how their properties are different to the bulk properties of the material. Like you I enjoy the multi-disciplinary side of things, my background is in physics, but I've recently had to learn a fair amount of organic chamistry as well.

[ivan astikov]

Have you got your eye on any of your colleagues as a potential "mad scientist", with Blofeld-like symptoms? You're not one, are you? We're trusting people on the inside like yourself to keep an eye on the nuttier element amongst your peers. :wink:

[Walker in Eternity]

Have you got your eye on any of your colleagues as a potential "mad scientist", with Blofeld-like symptoms? You're not one, are you? We're trusting people on the inside like yourself to keep an eye on the nuttier element amongst your peers. :wink:

I only have slight, "mad scientist" tendencies and am not working on weaponry, although I do like the idea of Dr Evil style "space lasers".

However, a lot of people have an innate fear of nanotechnology, probably in part due to Michael Crichton's book "Prey", which features a "self replicating nanotechnology swarm".

This is unlikely to be even a remote possiblity for a long time for a number of reasons:

Firstly nanoparticles are relatively costly to produce at present and, as far as I know, no self replicating particles have yet been produced.

Secondly, there is no currently viable method of nanoparticles interacting as a "distributed intelligence" network. I doubt there will be for some time.

Thirdly most, if not all, nanoparticles used in research today are just very small structures usually made up of either groups of atoms of a single element e.g. carbon nanotubes or buckyballs or metallic oxides e.g. zinc oxide nanowires. They are not, as is often depected in the media, very small machines. That is a nice idea and one that may one day come to fruition, but not in the near future.

So the possiblity of us all turning into grey goo is, at least for the foreseable future, highly unlikely.

[AllWalker]

Walker in Eternity, you are more than welcome to jump in! Organic electronics is one of those fields which I first think "wow, that's strange" followed by "wow, that's cool!". In other words, a great field.

As for what I want to do once I graduate, I am currently applying for jobs all over the place. A lot in non-nano areas. Frankly I'd be happy to leave the labs for a career in analysis for business or the government, or a science/technology consultant.

Grey goo theory is one of those things that pisses me off. It's like saying we should scrap computers because of the impeding robot uprising - it is bullshit,a nd even if it were plausible, computers do other things besides enslave humanity. The guy who first came up with grey goo theory recently retracted it, saying he was basing that on ideas at the dawn of the science which didn't pan out. He also said a lot of things like nanotechnology whould feature assembly from the atom up, whereas most of it is assembly from the molecule up.

Lastly, I think I'm a mad scientist type. I'm very obsessive about things, believe the world would be a better place were I ruling it, and I dropped out of my ethics course.

[The Logos]

Many thank for your replies, AllWalker. While having a discussion last night which was entirely unrelated to nanotechnology, the issues of renewable energy and living off the grid were raised, which reminded me of a possible nanotech application. I am wondering what the prospects might be for nanotechnology to revolutionize photovoltaics, bring down the capital costs associated with solar energy, and perhaps make the technology more versatile?

Perhaps quantum entanglement, as a means to coordinate elements in a nanosystem or as communicators. Most of my quantum physics comes from 2nd Year undergrad courses and books like A Brief History of Time, so I'm not the best person to ask.

Quantum entanglement might make for a good discussion elsewhere. I have been unsatisfied with its treatment in what I've read of the literature, which appears content to treat the phenomenon as emergent to physical law rather than physical process.

[AllWalker]

Many thank for your replies, AllWalker. While having a discussion last night which was entirely unrelated to nanotechnology, the issues of renewable energy and living off the grid were raised, which reminded me of a possible nanotech application. I am wondering what the prospects might be for nanotechnology to revolutionize photovoltaics, bring down the capital costs associated with solar energy, and perhaps make the technology more versatile?

It already has. There is a new approach to developing solar cells known as CIGS, or Copper-indium-gallium-selenide. Now, when I say new I don't mean it makes the old approach of silicon crystals obsolete, but this does provide an interesting alternative. How CIGS differ from regular solar panels is that they are durable, relatively cheap thin films. Imagine a wafer of metal you could stick on the top of a vehicle roof or even a helmet, which converts sunlight to electricity at around 10-15% (nearly 20% efficient in the labs, but that tells us nothing). It is lightweight, flexible and durable. I studied in detail a company which makes these things called Nanosolar, who are able to use a device similar to a printing press to make these films. It allows large scale manufacture of the material, which helps control the costs.

Another aspect to energy viability is energy storage. There are new developments being made in this area all the time, many related to nanotechnology. I have heard of one company which have improved the life, durability, capacity and recharge/dispersion rates of lithium batteries by replacing the graphite-based anodes commonly used with specially designed titanium oxide nanoparticles. Other approaches include metal oxide frameworks with incredibly high gas storage capacity, which might one day be used to store and transport hydrogen gas. Some people are also investigating the biochemical path, trying to store solar power in a similar way to the way plants do it.

There are many other approaches to renewable energy using nanotech, but these are the ones I can think of right now. Walker in Eternity would probably know several more ways of doing it in detail.

[Walker in Eternity]

In a nutshell there are a number of applications of nanotechnology to solar power. Basically, the type I work with, organics, needs nanoparticles just to work.

In a traditional solar cell (Silicon or similar semiconductor) a p-n junction is formed, this doesn't happen in polymeric materials (well it can, but it's not very efficient as many of the charge carriers recombine before they make it to the acceptor material). Instead the majority of OPV uses heterojunctions which are typically blends of polymers and nanoparticles, the most common of which is C[sub:m86mn03e]60[/sub:m86mn03e] (fullerene).

Other materials such as carbon nanotubes have been used in solar cells, basically the polymer donates electrons and the nanomaterial accepts them, it's a bit more complicated than silicon cells, because an intermediate stage of an exciton is created that needs to dissociate into free charge carriers.

Also needed for solar cells is a transparent electrode, this is typiclly made from indium tin oxide (ITO), but recently people have experimented with a number of alternatives including ZnO, silver nanowire mesh and a thin (>30nm) gold layer, all of which have potential.

Got to go to a meeting now, will try to add to this later.

[Walker in Eternity]

My thesis topic is called "Biocompatible Sensors based on Quantum Dots". This makes sense if you break it down...
Biocompaible = wont kill you if you are exposed to it
Sensors = detects stuff
Quantum Dots = microscopic particles of semiconductors. Have weird physical properties somewhere in between classical and quantum physics. Among these physical properties is high fluorescence - basically, they glow at particular colours when exposed to energy.

Any questions?

Since your thesis is about biosensors, are you familiar with using these to detect Alzheimer's disease? I read a paper recently suggesting that biosensor incorporating nanoparticle could potentially detect and possibly treat dementia and other diseases.

[AllWalker]

My thesis topic is called "Biocompatible Sensors based on Quantum Dots". This makes sense if you break it down...
Biocompaible = wont kill you if you are exposed to it
Sensors = detects stuff
Quantum Dots = microscopic particles of semiconductors. Have weird physical properties somewhere in between classical and quantum physics. Among these physical properties is high fluorescence - basically, they glow at particular colours when exposed to energy.

Any questions?

Since your thesis is about biosensors, are you familiar with using these to detect Alzheimer's disease? I read a paper recently suggesting that biosensor incorporating nanoparticle could potentially detect and possibly treat dementia and other diseases.

I've heard of biosensors for all kinds of things, but not Alzheimer's. What exactly would that detect? Would it locate a gene associated with it, or some kind of physical manifestation?

[Walker in Eternity]

According to the paper, it would look for proteins that are present when Alzheimer's occurs, therapies would include "neuroprotections against oxidative stress and anti-amyloid therapeuatics".

This link gives a good idea and links to the paper mentioned. I can't comment on whether it would be effective as medicine and disease treatment are well outside my area of expertise. Sounds good though if it's possible.

[BwanaBob]

What's the lowdown on the dangers of nanoparticles getting into places that they shouldn't, like in your lungs. ISTR that such an occurence is bad.

[AllWalker]

Ah yes, lungs. Here's the thing - the lungs are very good at flushing out particulate contaminants. Superb even. The problems are when a) there is too much stuff to remove, b) the stuff is especially toxic, or c) the particles are too small. There are quite a few nanoparticles in the (c) catagory.

But not all. Carbon nanotubes, for example - although single-walled nanotubes are small enough to create problems, multiwall nanotubes are fine. This says to me the lower limit for the size is very small indeed, though this is still an issue.

People, both rightly and wrongly, compare this to asbestos. Asbestos fibres are dangerous to the lungs in much the same way as some nanoparticles, but you or I are unlikely to encounter these particles in a harmful form even if their usage becomes widespread. It could be an isues working with them as raw materials, but we know the risks and so can minimise them.

There are other concerns, too. Nanoparticles might be able to penetrate cell walls and damage the internal workings, which could lead to cancer. It is uncertain at this stage how or what would happen, if anything.

[The Logos]

I am wondering if you, either AllWalker or Walker in Eternity, have read Michael Crichton's Prey, and if so have any comments on the broad-strokes plausibility of the science. Offhand, the notion of genetically engineering bacteria as factories for nanocomponents, and assembly sites for these components, strikes me as clever, and a research pathway likely being examined.

[AllWalker]

I have read it. Like all Michael Chrichton the science is kind of plausible yet total bullshit, but the story is good enough to get away with it.

Genetically engineerd bacteria could produce the proteins necessary for complex nanomachines. In fact, I fail to see any real alternative for the economic mass-synthesis of proteins. But that is the easy part - designing a nanomachine, even something woefully simple, is incredibly difficult. If it is based on proteins then the protein sequences have to be identified, and they have to be designed in such a way that they fit together. It's kind of like using Lego to build something like a moving claw, but without the ability to break it down into bricks. The parts come preassembled, often in the most horrible and unusable shapes. Then you have to worry about how they interact with each other.

When we become clever enough to worry about how to build complex nanomachines, this will probably be the way we do it. But right now it is difficult enough, though not impossible, to make simple things like cubes.

[AllWalker]

In the face of this, I am bumping this thread.

Edit: and moving it to Ask the Experts

[Unregistered]

Okay, here's a stupid question from somebody who knows nothing about this: you say it's hard to build something as simple as a cube. Why?

[AllWalker]

Okay, here's a stupid question from somebody who knows nothing about this: you say it's hard to build something as simple as a cube. Why?

Nature hates cubes.

By way of physical analogy, try to blow a cube soap bubble. Using a piece of wire and some detergent and water you can create one of those children's toys where you can blow bubbles. The beauty is you can make the shape of the blower, and thus the shape of the detergent film, any shape you like, be it regular or irregular. But once a bubble forms it always creates a sphere. In an ideal case it would form a perfect sphere, but things like atmospheric effects distort the shape slightly.

Nature hates cubes, but nature loves spheres. Given the chance, there are a lot of things that will collapse to form a sphere. Why?

Nature hates surface area.

Spheres have the lowest surface area to volume ratio possible. That is, for a given volume of material, packing it into a sphere means the least amount of the material is exposed to the air.

Surface areas are generally minimised by physical systems as they have a lot of energy, more than the bulk material. You can see this in a glass of water - if you are careful, the surface can support a needle, but once below the surface the needle sinks. The reason for this is to do with intermolecular bonding - in the middle of the water each water molecule can bond to its neighbours in all directions, but at the surface there are no neighbours above to bond to. This creates loose bonds, which are high in energy.

Now, most objects we experience in day to day life are too big and too rigid to collapse into a sphere. The surface of a soap bubble is not rigid, but rather it is constantly rearranging itself almost like a liquid, so it is able to collapse to a sphere very easily. A piece of paper, though, is far more static and so has no means to collapse into a sphere.

The tricky part comes when dealing with microscopic phenomenon. A piece of metal might be too rigid to collapse to a sphere when it is the size of your fist, but when it is a cluster of, say, 80 atoms, it doesn't take much shuffling to form a sphere. But there is more to it.

Suppose you have a cube 1 metre by 1 metre. Or 1 foot by 1 foot, it doesn't matter. It will have a certain volume and a certain surface area. Cut it into 2 equal sized pieces. The total volume is the same, but the surface area has increased - there are new surfaces where you cut. Cut these parts again, and again, and again. Each cut keeps the volume the same but increases the surface area.

The smaller something is, the greater its surface area to vloume ratio is. Another way of looking at this is visualising clusters of atoms again. A cluster of 3 atoms has all its atoms on the surface, a cluster of 100 might have just a few tucked inside, a cluster of 10,000,000 will have most of the atoms as part of the bulk. In other words, the smaller something is the more surface area it has per given amount of material, and since surfaces have energy, smaller things have more energy per amount of material.

So on the nanoscale, cubes are hard to create because spheres are highly preferred - they are easier to form on this scale and there is a stronger drive to do so. TLDR, but I wanted to do this question justice.

[Unregistered]

Thanks for the explanation. So when trying to arrange atoms in shapes that aren't round, are you copying the "architecture" from minerals then? I'm thinking of salt (http://www.michaelcutter.com/nat/exp...ltmolecule.gif) and pyrite and halite specifically. The reason they're in cubes is because of their atomic structure, right?

[AllWalker]

Right. Crystals can be the exception to this, as the bonds holding them together have incredibly high rigidity. While the atoms in, say, a cluster of metal can stick together however they want, in sodium chloride they must form an exact structure, due to the electromagnetic repulsion of the atoms. You can see this pattern even on the macroscopic level - blocks of salt have sharp, 90 degree surfaces. Any "smooth" smurface is made up of often visible smaller angular surfaces.

As for how they get something like silver to form a nanocube... well, that's not really my area, but it is the area of one of my friends. Thinking, thinking, thinking... I've seen a presentation on this... I don't know, I forget the exact details. But one thing I am fairly sure of is that while spheres can be made in open solution, nanocubes must be assembled on a surface. Surfaces have a weird way of completely overturning all rules about energy, thermodynamics and, in some cases, common sense. But this isn't mimicing ionic crystals - the results look similar but the forces governing them are completely different.

[Jaglavak]

What do you think about these teeny little radios? In particular I'm interested in the possibility of using them to link brain electrodes to a central transceiver. They could be powered by application of an external radio signal as with existing RFID tags. Thus overcoming nearly all the existing limitations on brain electrodes.

If something along these lines can be made to work, initial applications would be R&D and prosthetics. Mid term we're looking at sensory augmentation (telemetry from instruments) and direct mind to mind comm links.

In the long run - well, these things are two way radios. Besides bandwidth there's no theoretical reason why augmented senses can't become fully synthetic senses. And a comm channel could become full sensaround telepathy.

Moving right along to the paranoia, a comm channel could also be a control channel. I don't expect that people can be controlled like robots, but there's no obstacle to the application of serious pursuasion. Something to think about while it's still allowed.