NanoDiamond is Now Buckymesh Thursday, Jun 11 2009
nanotechnology 3:46 pm
NanoDiamond is a theoretical material with such an amazing strength-to-weight ratio that it challenges our intuitions about what is physically possible. Michael Richards, the creator of the nanoDiamond idea, recently renamed the material buckymesh, which is definitely an improvement. The term “nanodiamond” is commonly used to refer to small diamonds.
If fractal buckymesh can eventually be manufactured, you could make a pole out of it 1000 ft (304 m) long and it would only weigh a couple grams. Its material properties are highly variable depending on the quantity of internal holes. If it turns out that it could be made as strong as steel (quite plausible), you could fabricate a sword a couple hundred feet long that any adult could lift.
A rigid sword or pole of that length presents an interesting question — because perturbations can only move through the object at the speed of sound, how would the end of the pole behave if you moved it over 90 degrees in a fraction of a second? Would it take a second or two to move along with your motion? Or longer? If you turned around in circles very quickly, would the “rigid” pole come to resemble a spiral?
It seems to me that buckymesh would also be useful as a low-density, wide-area shield. Buckymesh may in fact be the material with the highest strength-to-weight ratio that is even physically possible.
June 12th, 2009 at 5:11 am
> A rigid sword or pole of that length presents an interesting question — because perturbations can only move through the object at the speed of sound, how would the end of the pole behave if you moved it over 90 degrees in a fraction of a second? Would it take a second or two to move along with your motion? Or longer? If you turned around in circles very quickly, would the “rigid” pole come to resemble a spiral?
You wouldn’t be able to move it quickly, because although the mass is small (1kg) the distance from the pivot to the Centre of Mass is very large (100 meters) so the torque rewuired to accelerated it through a given angular velocity would be huge.
Turning it would be as hard as turning a 100kg weight that was 1 meter long. But pushing it forwards/backwards would be as easy as pushing a 1 kg weight. Also, you wouldn’t be able to lift the far end off the floor because the centre of mass is so far away that similar torque considerations apply.
Yes, it challenges your intuitions.
June 12th, 2009 at 6:34 pm
I had not thought about a long skinny pole made of buckymesh, but I think that it would definitely bend, quite significantly most likely. In some configurations you might need to pre-bend it like pre-stressed steel is often done now.
By the way, if you check the mass estimates carefully, you will see that they assume a width of 80% of the length. So that estimate of 2.57kg for something 180m long is assumed to be a cylinder with a diameter of 144m. If the diameter was only 1 meter, it would probably weigh around 1 gram. So actually the torque would be quite small, and it would be quite easy to turn.
Of course making the pole long enough would eventually make it quite difficult to maneuver. Interesting thought experiments.
Michael
June 13th, 2009 at 1:12 pm
> If the diameter was only 1 meter, it would probably weigh around 1 gram. So actually the torque would be quite small, and it would be quite easy to turn.
Oh dear me, that is hard to imagine. you could poke someone with it from 100 meters and then rotate it through 360 degrees and poke them from the other side in a second. The closest material I can imagine is a hollow polystyrene cylinder, but that would have no strength.
You could actually make a 100 meter long sword out of it and kill people from a distance - as long as you were outside!
June 13th, 2009 at 1:13 pm
In fact if I’m not mistaken the main impediment to swinging this thing around would be air resistance.
June 13th, 2009 at 11:24 pm
> because perturbations can only move through
> the object at the speed of sound
The operating principle of the stock whip is that the end moves faster than the speed of sound, the crack of a whip is a small sonic boom.
If you moved a long bucky paddle around fast enough you should expect a sonic boom. But that would require a significant amount of energy expenditure (the area of the stock-whip that cracks is quite small). Whether the air resistance of the handle and the torque of holding it up would allow you to create your sonic boom would depend on how thin you can make this material while maintaining strength.
November 16th, 2009 at 12:30 pm
That certainly is hard to imagine. I always assume a certain mass is necessary for any degree of compressive strength.
For example with something this light you’d think you could take it in hand and crush it into something more dense.
November 19th, 2009 at 8:50 pm
Traclo, in any light material that you are used to, that is easily crushable, there exist only weak bonds between molecules, and a network of fracture plates running in multiple directions throughout the material. And the molecules themselves are very small. These 3 factors make it easy for the atoms to slide past each other, and the visible object to reduce in size and become denser. Buckymesh on the other hand is a single large molecule, with very strong covalent bonds, in an arrangement that pushes close to equally in all directions against any outside force attempting to squash it. Nothing like this exists in nature, so its hard for our intuitions to get a good idea of how it might feel were we to get our hands on a chunk. Buckymesh will compress somewhat, but non-destructively, and will bounce back to its original size when released.
November 19th, 2009 at 11:42 pm
I bet formula 1 is drooling over this. Make an entire car out of it, heaviest part is the driver.
December 1st, 2009 at 9:50 am
hell, make the driver out of it too.
a similar (or the same?)idea to the one explored in kim stanley-robinson’s brilliant mars trilogy where it is used to build, amongst other things, a space elevator.
December 4th, 2009 at 5:47 pm
lol
Only post number 9 stated a good application for this material: Space Elevators
That would be amazing.
It could also be used in many other ways that don’t involve people-killing swords or ridiculous racing vehicles.
Examples: Architecture - replacing steel and other materials. Transportation - making the frames of vehicles (land, flying, water, and space) so they can be safer and lighter.
And last but not least:
Replacing peoples bones so they can be like wolverine, only lighter than wolverine… and normal people
It all depends on the capacity to produce this thing in large amounts and versatile shapes.
But that it is a job for nanoscience of the future.
December 6th, 2009 at 10:09 am
Space elevators fail for other reasons, not the least of which is being outclassed in utility by a lofstrom type launch loop.
I think we’ll see buckymesh in sports equipment, aerospace, and body armor first, regardless of whether it could be put to better use elsewhere.
As for a sword, the speed you can swing it depends on the speed of sound through buckymesh, not the speed of sound through air, as that restriction applies in a vacuum. I don’t see a 100m+ sword being practical in any sense, as even if you could lift and swing it, your opponent would have an insane mechanical advantange for blocking it. 3 meters long might be practical tho, as long as you can overcome air resistance.