Roland Piquepaille writes "American researchers have built a carbon nanotube knife. According to the National Institute of Standards and Technology (NIST), this nanoknife will be used to cut and study cells. With this new tool, scientists and biologists will be able to make 3D images of cells and tissues for electron tomography, which requires samples less than 300 nanometers thick. And as cells are usually stored in wax for dissection, the researchers plan to test their nanoknives on a block of wax later this year. But read more for additional references and a picture of this nanoknife."
It doesn't seem that this tool will be available before a while. The researchers have "found that the welds were the weakest point of the nanoknife, and they are now experimenting with alternative welding techniques."
Wouldn't it be better to wrap or tie the carbon nanotube to a specially shaped tungsten needles rather than trying to weld them? Given the small size, welding directly to the needles seems like it could never work... better to rely on the strength of the nanotube than on the adhesive capacity of some other material.
All they really need to do is cut a nano-width-slot in each side of those tungsten prongs (creating a two-pronged fork on each prong). Then create a nano-axel by welding a small bead to each end of the nano-tube cutter (each bead being larger than the width between the fork prongs). Slide the nano-axel between the two tungsten forks. Pinch the ends of the forks together. Bingo! The nano-cheese-cutter can bend as much as it needs to and there are no fixed points to break.
Still, I guess I'd feel safer being thretened by one of these than a normal knife.. 'Give me all your money, or I'll cut the top layer of dead skins cells off your throat!'
Hath not a Jew eyes? Hath not a Jew hands, organs,
dimensions, senses, affections, passions? Fed with
the same food, hurt with the same weapons, subject
to the same diseases, healed by the same means,
warmed and cooled by the same winter and summer, as
a Christian is?
That's an interesting question- the thinnest possible nanotube knife, a single single-walled nanotube, is about 1 nanometer wide. I could imagine that a living cell membrane would self-heal as a nanotube knife passes through it, since the cell membrane is a dynamic fluctuating entity. Bigger problems would be created with the knife hit a large, covalently bound molecule, or a macromolecular assembly held together by strong non-bonded interactions (muscle fiber, microtubule, bone, extracellular matrix of various kinds). I'd think that many of those things wouldn't self-heal very well, but it's not totally obvious to me that the damage pathway would be wide enough that slowly passing a nanotube knife through say, an arm would make it fall off, or prevent it from healing back together over time. If I had to bet, I'd say yes, it would either fall off or end up attached so tenuously that it dies and falls off later, but who knows... (one problem is that a single nanotube is most likely not strong enough to slice through an entire arm)
If you read the original article instead of Roland Piquepailles summary (RTOAIORPS), you will notice that the cells are frozen:
For years, biologists have wrestled with conventional diamond or glass knives, which cut frozen cell samples at a large angle, forcing the samples to bend and sometimes later crack.
it's possible for either a silicon dioxide or obsidian knife to be one molecule thick too, so I don't think this nanotube knife is much improvement on some of the broken edges of other material that have been used for centuries.
Actually they did. The art of cutting thin slice is called microtomy [wikipedia.org]. Glass knife and diamond knife are used for microtomy. The advantage of glass knife is cost, the glass cost almost nothing. But glass knife doesn't last long, it gets blunt after 20 or 30 cuts. Also glass knife become blunt even you do nothing with it because glass is essentially fluid and the sharp edge has huge surface tension. Diamond knife lasts forever if you don't do anything wrong with it. But the diamond knife is pricey, a single knife can cost several thousand of dollars.
I have been doing microtoming for years. But I don't see how could this can be used to replace diamond knife. Basically we need to trim the sample to 0.1x0.25mm block and cut the block. This is small but still 100um. I at least need a knife of 150um wide to work on this. Nanotubes as long as 150um are not so well available at least for now. Then the knife is a 150um long 10nm thin wire, which I can not see with my eyes. How do I know the wire is stretched? And if it is stretched, during the cutting, the temperature and change from room temperature to -90 degree C. So how do I handle the thermal expansion? Also the problem troubled me mostly is how do I handle the section? When I am using a glass or diamond knife, the section and block fall to different sides of the knife, then I can use special tools to pick the section up. But when the wire cut through the sample, the section sticks back to the block. Also how much the wire knife cost and how long it can last? I can resharpen a 3mm diamond knife for $1500 after I made enough mistakes on it, which can be 5 or 10 years.
However, I really think this thing can be used as a wire saw to make MEMs [wikipedia.org].
That's all wel and good - but where is my Carbon-Monofilament garotting tool?
It'll be great, I can see the adverts now:
"See! New Nanoknife will cut straight through this small meteorite, and then through this tomato! But wait, there's more! If you call in the next 15 minutes we'll also include the amazing NanoJuicer, and a second Nanoknife for free. And as a bonus for the first 100 callers today, you'll also recieve this fabulous set of nano-forks..."
It's easy to get sizes mixed up. Nanometers, microns, angstroms, they all sound about the same.
300 nanometers is a third of a micron. Cells vary greatly in size and shape but a ballpark figure for human cells is 20 microns. So we're not talking about something that is all that "sharp" compared to the size of the object it aims to cut.
The 300 nm refers to the typical desired thickness of a slice of tissue. TFA states that typical glass knives need to be relatively thick to be strong enough, causing the sample to bend as it is being sliced. Conversely, the nano knife consists of a single carbon nanotube, stretched between two brackets. This is not a 'blade' in the traditional sense of the word, but is more akin to a cheese knife that is a wire under tension.
Wikipedia states that the diameter of a carbon nanotube is in the order of a few n
If the nanotube itself is the strongest part of the system why weaken it by welding it to the tungsten?
If they can manipulate objects at such a scale, They would surely get much better results by tying the nanotube to suitably shaped anchors.
Off the top of my head, a bowline [wikipedia.org] would be a good start, I'm sure some slashdot sailor could suggest a loop knot or hitch more suitable for a slippery line.
by Anonymous Coward
on Sunday November 26 2006, @09:41PM (#16997396)
The idea here is that the carbon nanotube may be able to replace the diamond [emsdiasum.com] or glass knives typically used for cutting biological specimens which have been embedded in a cured plastic resin. The knife and the sample to be cut are mounted on an ultramicrotome [leica-microsystems.com] and then sectioned at 50-90nm increments.
TFA states that the carbon nanoknife has yet to be tested cutting anything, so it's unclear to me the extent to which it could be used to replace a diamond knife. Also, a diamond or glass knife edge can be millimeters long, whereas this nanotube thread looks much shorter.
Could someone explain to me how these nano-tools are actually used? Obviously you can't use them by hand or you'd slice through a million cells with a twitch of a muscle and I wasn't aware that we had a mechanical means to control these things... If anyone could explain how they're used I'd be grateful.
How is it possible to make all shorts of nano-devices (motors, knifes etc) and it is not possible to make nano-processing units? Just out of curiosity...
Yeah, with all the recent announcements it's pretty hard to disregard Kurzweil's predictions. I was very sceptical of his claims until I realized that his timeline appears to be dead on so far.
That is so cool... (Score:4, Funny)
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"You call that a knife? THIS is a knife!"
"That's not a knife, that's a spoon."
"Ah, I see you've played knifey-spooney before!"
This is DANGEROUS (Score:2)
How hard is it to wrap a carbon nanotube? (Score:4, Interesting)
Wouldn't it be better to wrap or tie the carbon nanotube to a specially shaped tungsten needles rather than trying to weld them? Given the small size, welding directly to the needles seems like it could never work
Re:How hard is it to wrap a carbon nanotube? (Score:5, Informative)
Trying to tie or wrap those nanotypes would be more than futile.
Parent
Re: (Score:3, Funny)
So what you're saying is that friction's resistance would be useless?
Welding works (Score:2)
Man, I should work at the NIST
easy solution (Score:3, Interesting)
That's not a nanoknife, *this* is a nanoknife... (Score:3, Funny)
Give 'em time to build a "variable sword"... :-) (Score:2)
But, sigh, are there even theories that suggest the possibility of stasis fields?
Re:Give 'em time to build a "variable sword"... :- (Score:2)
If it's so thin (Score:5, Interesting)
Will it even trigger your nerves?
Re: (Score:1, Offtopic)
Hath not a Jew hands, organs, dimensions, senses, affections, passions?
Fed with the same food, hurt with the same weapons, subject to the same diseases, healed by the same means, warmed and cooled by the same winter and summer, as a Christian is?
If you prick us, do we not bleed?
Re: (Score:3, Funny)
Re:If it's so thin (Score:5, Interesting)
Parent
Re: (Score:2)
For years, biologists have wrestled with conventional diamond or glass knives, which cut frozen cell samples at a large angle, forcing the samples to bend and sometimes later crack.
How long before (Score:1)
Re: (Score:3, Insightful)
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And if you call within the next 15 minutes (Score:3, Funny)
I've already seen that (Score:5, Funny)
I saw my first nano knife when I brought my nano on the subway in New York. The guy took my wallet, too.
Obligatory (Score:1)
Re:Obligatory (Score:5, Interesting)
Actually they did. The art of cutting thin slice is called microtomy [wikipedia.org]. Glass knife and diamond knife are used for microtomy. The advantage of glass knife is cost, the glass cost almost nothing. But glass knife doesn't last long, it gets blunt after 20 or 30 cuts. Also glass knife become blunt even you do nothing with it because glass is essentially fluid and the sharp edge has huge surface tension. Diamond knife lasts forever if you don't do anything wrong with it. But the diamond knife is pricey, a single knife can cost several thousand of dollars.
I have been doing microtoming for years. But I don't see how could this can be used to replace diamond knife. Basically we need to trim the sample to 0.1x0.25mm block and cut the block. This is small but still 100um. I at least need a knife of 150um wide to work on this. Nanotubes as long as 150um are not so well available at least for now. Then the knife is a 150um long 10nm thin wire, which I can not see with my eyes. How do I know the wire is stretched? And if it is stretched, during the cutting, the temperature and change from room temperature to -90 degree C. So how do I handle the thermal expansion? Also the problem troubled me mostly is how do I handle the section? When I am using a glass or diamond knife, the section and block fall to different sides of the knife, then I can use special tools to pick the section up. But when the wire cut through the sample, the section sticks back to the block. Also how much the wire knife cost and how long it can last? I can resharpen a 3mm diamond knife for $1500 after I made enough mistakes on it, which can be 5 or 10 years.
However, I really think this thing can be used as a wire saw to make MEMs [wikipedia.org].
Parent
The perfect weapon (Score:2)
umm (Score:2)
Re: (Score:1)
There is a length of nano-cotton.
All they are waiting for is instructions on how to build a nano-thimble.
On this subject, the thread looks thinner than the knife, could they make a more effective cheese cutter?
Obligatory Niven Reference (Score:2)
Re: (Score:2)
But Wait: There's More! (Score:3, Funny)
It'll be great, I can see the adverts now:
"See! New Nanoknife will cut straight through this small meteorite, and then through this tomato! But wait, there's more! If you call in the next 15 minutes we'll also include the amazing NanoJuicer, and a second Nanoknife for free. And as a bonus for the first 100 callers today, you'll also recieve this fabulous set of nano-forks..."
Who cut the nano-cheese? (Score:2)
Re: (Score:1)
Furthermore, are you taking into account the possiblity that someone Moved Your Nano-cheese?
We could be talking Nano-ok of the North, here.
Size scales (Score:5, Informative)
300 nanometers is a third of a micron. Cells vary greatly in size and shape but a ballpark figure for human cells is 20 microns. So we're not talking about something that is all that "sharp" compared to the size of the object it aims to cut.
Re: (Score:3, Informative)
Conversely, the nano knife consists of a single carbon nanotube, stretched between two brackets. This is not a 'blade' in the traditional sense of the word, but is more akin to a cheese knife that is a wire under tension.
Wikipedia states that the diameter of a carbon nanotube is in the order of a few n
Were none of the researchers ever boy scouts? (Score:3, Interesting)
If the nanotube itself is the strongest part of the system why weaken it by welding it to the tungsten?
If they can manipulate objects at such a scale, They would surely get much better results by tying the nanotube to suitably shaped anchors.
Off the top of my head, a bowline [wikipedia.org] would be a good start, I'm sure some slashdot sailor could suggest a loop knot or hitch more suitable for a slippery line.
Hmmm.... (Score:2, Funny)
And in other news (Score:2, Funny)
The basics (Score:4, Informative)
TFA states that the carbon nanoknife has yet to be tested cutting anything, so it's unclear to me the extent to which it could be used to replace a diamond knife. Also, a diamond or glass knife edge can be millimeters long, whereas this nanotube thread looks much shorter.
Wow, this is just so high-tech! (Score:3, Funny)
Explain... (Score:2)
New tools for the Mohel (Score:2)
--
BMO
Nanoknifes, but not nano CPUs (for example)? (Score:2)
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As Mork would no doubt have said ... (Score:2)
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Re:Not enough 'nano' prefixes (Score:4, Informative)
Parent
Re: (Score:2)
Re: (Score:3, Interesting)