The holy grail of nano technology, assemble structures from the atom up!!!

[JoeRoccoCassara]

I really and truly honestly hope you are correct but then again I hope the Star Ship Enterprise will pull into orbit one day as a gift from an advanced civilazation that likes to watch Star Trek, it could happen but I'm not holding my breath.

 

Where is your creativity, curiosity, and imagination?

 

Question you're disbeliefs.

 

Many people on this forum are like those priests who wanted to crucify Einstein.

[Moontanman]

Where is your creativity, curiosity, and imagination?

 

Question you're disbeliefs.

 

Many people on this forum are like those priests who wanted to crucify Einstein.

 

I guess old age and reality has hemmed in my ability to fantasize.

[JoeRoccoCassara]

Ok but what will the nano bots be made of?

 

Energy might work.

 

No such thing as free quarks.

 

That's why the nano-bots take the quarks from other atoms.

 

Meaningless term. Try Degenerate matter, still won't work but at least it's accurate.

 

It will work.

 

Still weighs or masses the same, no help there at all.

 

Still weighs the same but it doesn't sink to the center of the Earth, improvement there.

[JoeRoccoCassara]

I guess old age and reality has hemmed in my ability to fantasize.

 

Let's let my argument become fantasy first.

[JoeRoccoCassara]

Let's further explore these energy nano bots, the smallest nano bots we could make using matter could shoot pulses that magnetically blow atoms and quarks apart, and more, smaller, pulse charges could be used to move these quarks and atoms into place after a long struggle that requires that percision that only machines could produce.:smilingsun:

[freeztar]

**Moved from Engineering to the Watercooler**

[Moontanman]

Quote:

Originally Posted by Moontanman

I guess old age and reality has hemmed in my ability to fantasize.

 

 

Possibly I should said reality and old age has diminished my ability to delude myself into believing fantasy. I still like fantasy but I don't believe it any more.

[CraigD]

I'm curious about how this may affect the world. I think a replicator will still need particles to be of some use, but where will it take them from? Will it use the gases of our atmosphere? You can't create something from nothing, can you?

Correct.

 

Most descriptions of nano-fabricators or “replicators” like the “personal fabricator” described in the BBC documentary assume that part of the swarm of nanobots in it will be dedicated to taking apart any sort of feed stock atom-by-atom, so as long as you feed it something with the right atoms, it can reassemble them into whatever its programmed to make. Fiction writers commonly describe throwing sand “for silicon and oxygen”, water “for hydrogen”, twigs and sticks or just good (for carbon and nitrogen) into a hopper.

 

These “atom assemblers” wouldn’t be able to make carbon into iron, gold, platinum, or plutonium, but as common and rare metals are useful mostly because of the ease with which they can be fabricated using old-fashioned, macroscopic techniques, they wouldn’t need to. Building materials atom-by-atom, carbon, silicon, and other readily available elements can in principle do nearly anything we currently do with less available elements. Useful chemical properties of metals like silver and platinum can, in principle, be mimicked by nanometer scale structures made of other elements. Color pigments that in the present day use various metals could be made nanoscopically using diffraction and scattering effects – examples of this in nature are bird feathers, which can be bright green and blue, even though they’re made of the same drab-colored keratins as ordinary animal hair.

 

In addition to “you can’t create something from nothing”, you can’t do mechanical work – moving individual atoms around is at least as much work as moving the same atoms in their usual large collections – without energy. So in addition to needing feed stock – which should be pretty much free - personal fabricator will need to be “plugged in” to some power source, so among the first things you’d likely want to fabricate would be lots of photovoltaic panels to cover every available sunlit surface, and ultracapacitors to store the energy.

[JoeRoccoCassara]

Correct.

 

Most descriptions of nano-fabricators or “replicators” like the “personal fabricator” described in the BBC documentary assume that part of the swarm of nanobots in it will be dedicated to taking apart any sort of feed stock atom-by-atom, so as long as you feed it something with the right atoms, it can reassemble them into whatever its programmed to make. Fiction writers commonly describe throwing sand “for silicon and oxygen”, water “for hydrogen”, twigs and sticks or just good (for carbon and nitrogen) into a hopper.

 

These “atom assemblers” wouldn’t be able to make carbon into iron, gold, platinum, or plutonium, but as common and rare metals are useful mostly because of the ease with which they can be fabricated using old-fashioned, macroscopic techniques, they wouldn’t need to. Building materials atom-by-atom, carbon, silicon, and other readily available elements can in principle do nearly anything we currently do with less available elements. Useful chemical properties of metals like silver and platinum can, in principle, be mimicked by nanometer scale structures made of other elements. Color pigments that in the present day use various metals could be made nanoscopically using diffraction and scattering effects – examples of this in nature are bird feathers, which can be bright green and blue, even though they’re made of the same drab-colored keratins as ordinary animal hair.

 

In addition to “you can’t create something from nothing”, you can’t do mechanical work – moving individual atoms around is at least as much work as moving the same atoms in their usual large collections – without energy. So in addition to needing feed stock – which should be pretty much free - personal fabricator will need to be “plugged in” to some power source, so among the first things you’d likely want to fabricate would be lots of photovoltaic panels to cover every available sunlit surface, and ultracapacitors to store the energy.

 

So couldn't you make metals significantly lighter, so you could have 50,000-20,000 pound space shuttles that are the same size as Orion?

 

And couldn't you make new chemical rocket fuel that's more powerful than anything in nature?

[CraigD]

So couldn't you make metals significantly lighter, so you could have 50,000-20,000 pound space shuttles that are the same size as Orion?

I can’t see how you could use nanotech to make metal structural materials more than slightly less massive.

 

Because metals have regular crystal structures, their density (mass divided by volume) is the same whether they are forged the old fashioned way, or some more modern way, such as vapor deposition, or, someday, individual atom nano-assembly. Although nano-assembly could allow metal parts to be made that were so free of microscopic defect that a smaller part could be trusted to do what current engineering safety margins require a larger part to do, and/or make parts with optimal qualities, such improvements would, I think, be slight, and possibly unwise, as by eliminating safety margins, you’d be placing a lot of trust in nano-assembler software.

 

This is likely unimportant, however, since even present-day technology is already preferring non-metal elements – primarily carbon - for structures such as airframes. Much lighter and stronger than metals, such materials (eg: carbon fiber) already are used in most new high-performance airplanes (2004’s SpaceShipOne and the soon-to-be flown SpaceShipTwo – though arguably not really worthy of the name “spaceship” – are primarily carbon fiber), sports equipment, etc, leading many technologists to describe “the age of metal” as a bygone technological age.

 

Current carbon fiber technology is similar to weaving, producing essentially thread made of short graphene strands. Nanotech promises to greatly improve this, producing large tetrahedrally bonded crystals – in other words, diamond – or very long single graphenes While large diamond crystals are at present very expensive gemstones, in the future, via nanotech, diamond crystals massing hundreds or many thousands of kilograms promise to be an amazingly good engineering material, leading many futurists to describe this future (which some anticipate being less than a decade, others more than a century, away) as “the diamond age”. For example, Neal Stephenson’s 1995 novel “The Diamond Age”, describes a future dominated by nanotech, in which Eric Drexler is regarded a nearly mythological hero (rather than something of a charlatan and a con man, as many technologists presently consider him, or simply wishful and naïve, as technologists such as 1996 Chemistry Nobel laureate and discoverer of buckminsterfullerene Richard Smalley).

 

While, IMHO, there’s a general consensus among technologists that nanotech of some sort will result in much improved engineering materials, there’s not much of a consensus on what this technology will, in detail, be like. My personal opinion is that it won’t be much like the “free-swimming” nanobots Drexler describes, but will involve purely mechanical “dry nanotech”, as opposed to biological life-like “wet nanotech”. I think that it’s character will derive from present day devices like atomic force microscopes and laparoscopic surgical instruments. My opinion is mostly a guess – as, I think, is the opinion of most technologists, including the ones interviewed in the BBC program video linked in post #1.

And couldn't you make new chemical rocket fuel that's more powerful than anything in nature?

I don’t think so.

 

Chemical rocket fuels are typically liquids or amorphous, “gummy” solids. They have no crystal structure to be assembled into, so nano-assembly technology appears of little application to them.

 

However, this too is likely to be irrelevant. As Moontanman’s signature suggests, many people don’t think chemical-fuel rockets have a very promising future. Though I’m not confident that the design being pursued by the folk at nuclearspace.com will work, I agree that something radically different than how we’ve launched spacecraft for the past half century is needed.

[Moontanman]

I've given it some thought and I can see a way nano tech might be able to make metal objects with a lot less mass but even stronger than current metals are. Has any ever given any thought to how Styrofoam can be so light and yet so strong? Melt Styrofoam down and you get a thin sheet of very weak plastic. All you have to do is make metal foam! A ton of titanium could make an enormous amount of titanium foam, enough to make a complete space shuttle and maybe the rocket it launches on. Nano bots might be able to construct things out of metal foam or it's slowly constructed equivalent. Of course metal foams have to be made in a very low gee environment, orbit in other words so nano bots aren't really necessary to make metal foam. An ounce of something like aluminum or titanium could make a very large object if it was made into foam. As for rocket fuel, metallic hydrogen seems to have some real possibility as a mono propellant but even though it would be better than chemical it still wouldn't touch nuclear. Nano bots wouldn't make any difference to metallic hydrogen.

[modest]

Although I'm not at all familiar with nanotechnology futurism, I would tend to agree. Arranging atoms one by one would presumably allow for a "material" to be constructed with any chosen architecture. Materials with internal structure resembling something like the steel frame of a skyscraper with trusses and whatnot would greatly lighten something of equal strength - that, at least, sounds intuitively possible to me.

 

If, for example, we could manipulate carbon nanotubes to achieve junctions such as this,

 

-source

 

then I believe we could make some extremely light and extremely strong things much like we do on a macroscopic scale now (like suspension bridges).

 

~modest

[JoeRoccoCassara]

If we could manipulate the structures of atoms, and piece together neutrons and protons, and quarks, then we could change the density and all and all strength of materials themselves by literally building at the subatomic level, building from the particle up.

 

What I am talking about is an atom that looks like a nano tube, and a bunch of these atoms might make up a super duper strong nano tube, stronger than a nano tube made just from regular atoms. Which means you could make it lighter and stronger than you ever could with plain atomic manipulation. Structured atoms that are like supports that make up a nano support, and nano supports could be the nano tubes that make up a metal.

 

If nano bots could shoot small electromagnetic charges that are unstable and explode a after they've been created, and make them stable enough to last long enough to hit and explode in the perfect spot on a subatomic particle to actually move it in a certain direction, and then fire many more to actually propel sub atomic particles into a structure with the thrust from the specific impulse of these little nuclear pulses, then we could build atoms with specific structures in the way I'm proposing by propelling them toward each other.

 

It would be like positioning chunks of metal with kinetic explosions.

 

This process could make titanium a thousand times lighter.

[JoeRoccoCassara]

Delete

[CraigD]

I've given it some thought and I can see a way nano tech might be able to make metal objects with a lot less mass but even stronger than current metals are.

Until someone has actually assembled at least a fine (at least a few hundred atoms in cross-section diameter) metal wire using Drexlarian nano-assembly techniques, and its strength tested, the strength of such materials remains a tenuous maybe to me.

 

Put into ordinary blacksmith terms, atom-at-a-time nano-assembly is a annealing/tempering technique, arranging the crystalline structure of the metal to produce desired characteristics. Traditional techniques rely on metals’ “self assembly” characteristics. Heated and cooled slowly, the structure is more amorphous, so is weaker but more ductable/malleable/flexible. Heated and cooled quickly (“quenched”), the crystalline faces are more aligned, so the piece is stronger, but more brittle. The blacksmith’s art comes in large part from the need of a typical metal piece to be hard and brittle in some places (eg: a contact surface or sharp edge), and soft and malleable in others (eg: the core), resulting in a piece that wears well and doesn’t break.

 

In principle, a nano-machine could do this exactly, according to a “blueprint” derived from a precise simulation of the performance requirements of the piece. My uncertainty comes from not knowing how close to ideal ordinary metalworking techniques are. If they’re close, a “perfect” piece assembled nano-mechanically might be only slightly better than an ordinary piece. If they’re far from ideal, it might be much better.

 

As I noted above, however, I don’t think this much matters, as the only reason we traditionally use metals is because of their self-assembly characteristics. Heat ore, collect the molten metal, skim it, pour it into a mold then work the resulting piece in various ways, and you get a useful tool or structural material. Try this approach with carbon, and you don’t get wonderful fullerene fibers or diamond super-building material, but crumbly ash. Even if you can coax a non-metal into one of these crystalline forms, you can’t stamp, role, or hammer it into marvelous structures like the ones linked from modest’s post.

 

The greatest promise of nanotech seems to me to be not in improving the fabrication of present-day materials, but allowing the fabrication of materials presently impossible.

 

Discussion of how to actually do this is what puts technologists like Drexler and Smalley at odds bordering on animosity (the 10/2004 Wired article “The Incredible Shrinking Man” gives a good perspective on this). In short, Drexlerians envision it being done by swarms of autonomous nanobots, while “conservative” nanotechnologists assume that more traditional self-organizing material characteristics and “bulk” fabricating techniques will continue to be needed. In between these extremes are various mixtures of the two, constituting, I think, the “mainstream”. I imagine myself a spectator in the mainstream’s cheering section. :)

Has any ever given any thought to how Styrofoam can be so light and yet so strong?

As structural materials go, polystyrene foam isn’t very strong, though it can be pretty light. It’s mostly useful for insulation and floatation.

Melt Styrofoam down and you get a thin sheet of very weak plastic.

If you can manager to get all the dirt and bubbles out of it, melted Styrofoam is the same stuff as the high impact polystyrene used in injection and vacuum molded parts. These parts can be thin or thick, and fairly strong - 46-60 N/m^2 tensile strength, about 1/4th the strength of cast iron, 1/10th that of machine steel. (sources: wikikedia articles “Polystyrene and “Tensile strength”.

All you have to do is make metal foam!

According to its wikipedia article, metal foam’s strength decreases as its density decreases. This agrees with my experience with a block of aluminum foam. You could dent it with bare hands (it was covered in handprints), and it floated :). Despite this lack of tensile strength, the wiki mentions that, in addition to a useful controlled-crumble impact-absorbing material, foamed metal can be, but hasn’t widely been used as a structural material (presumably for stiffening, not compressive or tensile strength).

 

I’m pretty sure that even if precisely assembled my nano-machines, metal foam would have about the same tensile strength as a solid part if equal cross-section area, so would be only slightly more useful due to increased off-axis stiffness, and less useful due to the need to be sheathed and capped to avoid crushing.

Of course metal foams have to be made in a very low gee environment, orbit in other words

I’m pretty certain that metal foams are currently made under ordinary, 1 gee conditions.

An ounce of something like aluminum or titanium could make a very large object if it was made into foam.

The wikipedia article says that typically 75-95% of the volume of a metal foam is the gas used to foam it. Since the length-to-volume relationship is [math]x : x^3[/math], a typical metal foam object would be 1.6 to 2.7 times as tall as a solid one of the same mass – significantly larger, but not IMHO amazingly so.

 

By comparison, the Statue of Liberty, which consists of a thin copper skin over a steel frame, is about 97.5% empty space. It masses about the same that it would if it had been molded as a solid piece of foamed copper - though according to this “brief history of metal foams”, the best I’ve found on the internet, the first metal foams weren’t made until the late 1940s, and really good methods not found until the late 1950s through mid 1960s, so there’s not possibility that the 1880s statue could have been made that way, even had someone wanted to.

 

Return to the old “end of the metal age” theme, we can note that various science fiction writers have imagined that nanotech might produce foam-like materials much less dense than metal foams, so low-density that they’d actually be less dense than air. This could make for a waste-disposal nightmare, as rather than settling to the ground to be degraded like ordinary ash, dead nanomachines might float nearly forever at an altitude where their density matched that of air, producing a global “nano-smog” layer.

 

We don’t need to worry about this happening with metal foams. :) For aluminum, density [math]2.7 \,\mbox{g/cm}^3[/math] to be lighter than sea-level air, density [math]0.0012 \,\mbox{g/cm}^3[/math], it would have to be over a hundred times “foamier” than a 95% foam.

[Moontanman]

Until someone has actually assembled at least a fine (at least a few hundred atoms in cross-section diameter) metal wire using Drexlarian nano-assembly techniques, and its strength tested, the strength of such materials remains a tenuous maybe to me.

 

Put into ordinary blacksmith terms, atom-at-a-time nano-assembly is a annealing/tempering technique, arranging the crystalline structure of the metal to produce desired characteristics. Traditional techniques rely on metals’ “self assembly” characteristics. Heated and cooled slowly, the structure is more amorphous, so is weaker but more ductable/malleable/flexible. Heated and cooled quickly (“quenched”), the crystalline faces are more aligned, so the piece is stronger, but more brittle. The blacksmith’s art comes in large part from the need of a typical metal piece to be hard and brittle in some places (eg: a contact surface or sharp edge), and soft and malleable in others (eg: the core), resulting in a piece that wears well and doesn’t break.

 

In principle, a nano-machine could do this exactly, according to a “blueprint” derived from a precise simulation of the performance requirements of the piece. My uncertainty comes from not knowing how close to ideal ordinary metalworking techniques are. If they’re close, a “perfect” piece assembled nano-mechanically might be only slightly better than an ordinary piece. If they’re far from ideal, it might be much better.

 

As I noted above, however, I don’t think this much matters, as the only reason we traditionally use metals is because of their self-assembly characteristics. Heat ore, collect the molten metal, skim it, pour it into a mold then work the resulting piece in various ways, and you get a useful tool or structural material. Try this approach with carbon, and you don’t get wonderful fullerene fibers or diamond super-building material, but crumbly ash. Even if you can coax a non-metal into one of these crystalline forms, you can’t stamp, role, or hammer it into marvelous structures like the ones linked from modest’s post.

 

The greatest promise of nanotech seems to me to be not in improving the fabrication of present-day materials, but allowing the fabrication of materials presently impossible.

 

Discussion of how to actually do this is what puts technologists like Drexler and Smalley at odds bordering on animosity (the 10/2004 Wired article “The Incredible Shrinking Man” gives a good perspective on this). In short, Drexlerians envision it being done by swarms of autonomous nanobots, while “conservative” nanotechnologists assume that more traditional self-organizing material characteristics and “bulk” fabricating techniques will continue to be needed. In between these extremes are various mixtures of the two, constituting, I think, the “mainstream”. I imagine myself a spectator in the mainstream’s cheering section. :)As structural materials go, polystyrene foam isn’t very strong, though it can be pretty light. It’s mostly useful for insulation and floatation.If you can manager to get all the dirt and bubbles out of it, melted Styrofoam is the same stuff as the high impact polystyrene used in injection and vacuum molded parts. These parts can be thin or thick, and fairly strong - 46-60 N/m^2 tensile strength, about 1/4th the strength of cast iron, 1/10th that of machine steel. (sources: wikikedia articles “Polystyrene and “Tensile strength”.According to its wikipedia article, metal foam’s strength decreases as its density decreases. This agrees with my experience with a block of aluminum foam. You could dent it with bare hands (it was covered in handprints), and it floated :). Despite this lack of tensile strength, the wiki mentions that, in addition to a useful controlled-crumble impact-absorbing material, foamed metal can be, but hasn’t widely been used as a structural material (presumably for stiffening, not compressive or tensile strength).

 

I’m pretty sure that even if precisely assembled my nano-machines, metal foam would have about the same tensile strength as a solid part if equal cross-section area, so would be only slightly more useful due to increased off-axis stiffness, and less useful due to the need to be sheathed and capped to avoid crushing.I’m pretty certain that metal foams are currently made under ordinary, 1 gee conditions.The wikipedia article says that typically 75-95% of the volume of a metal foam is the gas used to foam it. Since the length-to-volume relationship is [math]x : x^3[/math], a typical metal foam object would be 1.6 to 2.7 times as tall as a solid one of the same mass – significantly larger, but not IMHO amazingly so.

 

By comparison, the Statue of Liberty, which consists of a thin copper skin over a steel frame, is about 97.5% empty space. It masses about the same that it would if it had been molded as a solid piece of foamed copper - though according to this “brief history of metal foams”, the best I’ve found on the internet, the first metal foams weren’t made until the late 1940s, and really good methods not found until the late 1950s through mid 1960s, so there’s not possibility that the 1880s statue could have been made that way, even had someone wanted to.

 

Return to the old “end of the metal age” theme, we can note that various science fiction writers have imagined that nanotech might produce foam-like materials much less dense than metal foams, so low-density that they’d actually be less dense than air. This could make for a waste-disposal nightmare, as rather than settling to the ground to be degraded like ordinary ash, dead nanomachines might float nearly forever at an altitude where their density matched that of air, producing a global “nano-smog” layer.

 

We don’t need to worry about this happening with metal foams. :) For aluminum, density [math]2.7 \,\mbox{g/cm}^3[/math] to be lighter than sea-level air, density [math]0.0012 \,\mbox{g/cm}^3[/math], it would have to be over a hundred times “foamier” than a 95% foam.

 

Oh well, so much for my metal foam thread, I must be operating on old info, I thought the idea of a metal foam I-beam, light as balsa wood and strong as steel was not only possible but a great idea I guess my idea is just not possible.

[JoeRoccoCassara]

If we could manipulate the structures of atoms, and piece together neutrons and protons, and quarks, then we could change the density and all and all strength of materials themselves by literally building at the subatomic level, building from the particle up.

 

What I am talking about is an atom that looks like a nano tube, and a bunch of these atoms might make up a super duper strong nano tube, stronger than a nano tube made just from regular atoms. Which means you could make it lighter and stronger than you ever could with plain atomic manipulation. Structured atoms that are like supports that make up a nano support, and nano supports could be the nano tubes that make up a metal.

 

If nano bots could shoot small electromagnetic charges that are unstable and explode a after they've been created, and make them stable enough to last long enough to hit and explode in the perfect spot on a subatomic particle to actually move it in a certain direction, and then fire many more to actually propel sub atomic particles into a structure with the thrust from the specific impulse of these little nuclear pulses, then we could build atoms with specific structures in the way I'm proposing by propelling them toward each other.

 

It would be like positioning chunks of metal with kinetic explosions.

 

This process could make titanium a thousand times lighter.

 

 

Would this work???