# Self assembling nano technology



## Brian G Turner (Nov 23, 2003)

http://www.newscientist.com/news/news.jsp?id=ns99994406

excerpt:



> A functional electronic nano-device has been manufactured using biological self-assembly for the first time.
> 
> Israeli scientists harnessed the construction capabilities of DNA and the electronic properties of carbon nanotubes to create the self-assembling nano-transistor. The work has been greeted as "outstanding" and "spectacular" by nanotechnology experts.
> 
> ...


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## Rosemary (Jan 4, 2006)

Look what else this nano technology might do Brian.....

*Excerpt from the Wikipedia *




*Potential risks            Goo*

     An often cited worst-case scenario is "grey goo", a hypothetical substance into which the surface objects of the earth might be transformed by self-replicating nanobots *running amok*, a process which has been termed global ecophagy. Defenders point out that smaller objects are more susceptible to damage from radiation and heat (due to greater surface area-to-volume ratios): nanomachines would quickly fail when exposed to harsh climates. This argument depends on the speed of which such nanomachines might be able to reproduce.
  Recently, new analysis has shown that this "grey goo" danger is less likely than originally thought. K. Eric Drexler considers an accidental "grey goo" scenario extremely unlikely and says so in later editions of _Engines of Creation_. The "grey goo" scenario begs the Tree Sap Answer: what chances exist that one's car could spontaneously mutate into a wild car, run off-road and live in the forest off tree sap? However, other long-term major risks to society and the environment have been identified.
  A variant on this is "[Green Goo]", a scenario in which nanobiotechnology creates a self-replicating nano machine which consumes all organic particles, living or dead, creating a slime -like non-living organic mass.
  Both of these would, however, be limited by the same mechanism limiting all life forms (who generally already behave this way): available energy.
*Poison/Toxicity*

  For the near-term, critics of nanotechnology point to the potential toxicity of new classes of nanosubstances that could adversely affect the stability of cell membranes or disturb the immune system when inhaled or digested. Objective risk assessment can profit from the bulk of experience with long-known microscopic materials like carbon soot or asbestos fibres.
  There is a possibility that nanoparticles in drinking water could be dangerous to humans and/or other animals. Colon cells exposed to nano titanium dioxide particles have been found to decay at a quicker than normal rate. Titanium dioxide nanoparticles are often used in sunscreens, as they make them transparent, compared to bigger titanium dioxide particles, which make the sunscreen appear white.


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## Rosemary (Jan 7, 2006)

Have just heard that they are actually producing nano materials which can be used for a variety of ways.  

I couldn't find anything on the web...but from what I can gather it will help eliminate some Greenhouse Gas Emissions.  It will be used in the production of cars, making them run of solar energy as the nano material will act as a solar panel.


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## chrispenycate (Jan 18, 2006)

Note that all these problems come from self replicating nano technology, which is still very science fiction. Consider what is required for nano technology to work at all :- in a package no bigger than a bacterium, you must pack a power source, a manipulative  capability, some form of sensory system, a recognition system and a control system. Several orders of magnitude more complicated than the use of DNA to manufacture a transistor as described in the article, but visualisable (is that a word ? If not it ought to be) A batch of these designed, for example, to attack cancer, would come out of the factory with their batteries fully charged, be injected into the patient and activated, and would recognise the difference between healthy and cancerous cells, zap the latter and ignore the former, until they break down or the battery goes flat, at which point they « die » and are excreted by the body’s own natural systems. All cheer, run tests, either inject another dose or not. Pretty complicated, particularly the system used to recognise the different cells, but within dreaming range.
A von Neumann machine has to contain a blueprint completely defining itself (including the blueprint), the analog of DNA, a tool kit complete enough to build another self, a continuously rechargeable power supply, the ability to recognise all the elements required in its construction, and to extract them from the surrounding environment and store those it has until they’re all available and a second self can be created. If I were going to try for a von Neumann machine I’d start by building something like an asteroid mining system, with a factory building space bulldozers which would harvest all the minerals reqired to build more bulldozers, extractor plants and factories, and the instructions copied into the newborn factory from the computer in its « parent ». More a von Neumann ecology than an organism (and even then, I’d put some humans into the loop as a control factor to start with) Squeezing that down to subcellular size – I’d cheat. I’d take a system that already did all the complicated bits, and tailor it for the given job. The system ? A living cell, evidently, probably a bacterium- all your control system already in place, sensory system installed, power supply works. And we know that, while runaway bacterial action has been extremely inconvenient in the past, there’s never been any risc of it converting the planet into grey goo (perhaps the inhabitants- I suppose we’d better guard against that, even if there are a few people… Presumably there would be some trace element that would be required for their reproduction that we could withhold to eliminate them when teir function was completed. However, most proponents of self replicating nanotech imagine teensy weeny metal robots, containing even teensier weenier computers, into which we download ever so tiny operating systems (presumably « demicrobed » rather than « debugged », Programmed DNA for storage, maybe ? It’s already proved to work, if we can design a molecular scale reader, and has a built in copy function, very convenient. The power of the processor would be very limited – it takes a certain number of molecules to build a switch, a certain number of gates to perform a function- and the final size aimed for is smaller than one transistor on a present microprocessor (the technology in the first post would bring down this size considerably, but generates individual transistors rather than arrays) How about bionic microbes (the six billion dollar man’s sex life was somewhat glossed over in the programs I saw) combining the tried and tested microbe reproduction system and control interface with mechanical manipulation and programming ? I don’t care what I’m dying of, you’re not injecting that stuff into me- and the sci-fi stories where it knows exactly what every part of a correctly functioning human being should be like, and rebuilds you following its template whenever you get sick, or wounded, or old. Someone else, if you please.


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## HieroGlyph (Jan 23, 2006)

I was was rather engrossed until:



> ...eliminate them when teir function was completed...


 
which brought me back to Earth!

All highly hypothetical!

Current technology can do nothing of the sort.
Unless by accident. The scale of accident is in proportion to the time scale required, as well. Hence, sit upon your laurels and relax...


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## chrispenycate (Jan 24, 2006)

And I must learn to spread out my posts more, even if they do tend to take up quite a lot of space as it is. I'm sorry about the typo.

The moral is "Don't worry Rosemary, not only you (and Chris) will have disappeared before this problem becomes urgent, but probably your delightful grandchildren too."

Of course I hypothet - even as the keyboard cools down I'm working on an alternative developement technique (based loosly on the "boppers" in Rudy Ruckers "software" series, but suitably mutilated to fit my needs) of "evolving" nanotech, by survival of the fittest and modifying the enviroment to select for the characteristics desired. Splendidly dangerous, as you'd build for high mutation capability (to reduce waiting times), transfer of potentially useful characteristics by eating (when you eat another nanobot for materials to reproduce with, some of it's characteristics are maintained. If these are useful, your offspring have a greater chance of survival. Almost as good as sex, and cross species, too.) So, in a situation where the things are used to clean up a toxic chemical spill, say, the odds are proportionately higher that one will develope that doesn't need its daily dose of yttrium to survive, and will spread across the countryside eating insecticides…


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## HieroGlyph (Jan 24, 2006)

The more you think about it the more difficult it seems to be:

To create a nanobot like this _"grey goo"_ ?

In overview, it would be like creating a whole new _life-form!_

So it would take a rather great deal of time and resources, as already stated by Chris.

This very thread title does not help, really. The transistors shrinkers! might be better. And the info. is 3 years old now...


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## chrispenycate (Jan 24, 2006)

HieroGlyph said:
			
		

> The more you think about it the more difficult it seems to be:
> 
> To create a nanobot like this _"grey goo"_ ?
> 
> ...


Not merely a new life form - new type of life form not based on the model *all* terestrial life uses. An _interesting_ challenge. with the example before us of Microsoft, who, with problems several million times less complex, can still manage to leave one or two minor _oversights_ in their programming - and the nanoptimists are talking about _medical_ uses - thank you, I'll just cut my throat, sounds less painful. It's not merely the miniturisation, though that's fairly mind boggling (did you read the one where, instead of electronics, which were considered too big, they used a mechanical Babbage engine, with benzine rings as cog wheels) but the fact we aren't up to cockroach intelligence on the robots run by external computers yet- how can we hope to squeeze it onto a grain of dust? And a grain of dust is far too big, particularly if you compare the weight of the nervous sysstem to the total weight of any lifeform we know.


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## HieroGlyph (Jan 24, 2006)

Yes, thats the point I try to make about the more you think about it...

...since thinking is all that it is, for NOW.

The title is misleading. And the fact it is linked with actual scientific research lends itself to some authenticity that IS NOT quite the case.

Huge 'leaps' needed, as Chris can continuously, unabatedly allude to - 

For now though, this is still sci-fi and cant be spoken too much within this section, I reckon.


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## The_Cosmic_Quest (Feb 17, 2006)

I read about this in Michael Crichton's novel, "Prey"


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