Sheffield Scientists Have Revolutionized the Electron Microscope 90
An anonymous reader writes "For over 70 years, transmission electron microscopy (TEM), which 'looks through' an object to see atomic features within it, has been constrained by the relatively poor lenses which are used to form the image. The new method, called electron ptychography, dispenses with the lens and instead forms the image by reconstructing the scattered electron-waves after they have passed through the sample using computers. Scientists involved in the scheme consider their findings to be a first step in a completely new epoch of electron imaging. The process has no fundamental experimental boundaries and it is thought it will transform sub-atomic scale transmission imaging."
holography? (Score:2)
didn't read TFA but did they just reinvent holography? http://en.wikipedia.org/wiki/Holography [wikipedia.org]
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no, they are just are using a synthetic aperture
http://en.wikipedia.org/wiki/Synthetic_aperture_radar
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Sheffield, yeaaaaah, home to two shit football teams and the greatest condiment known to man, Henderson's Relish [hendersonsrelish.com]
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No. Read TFA (which is s bit short on detail).
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I think the only people who would understand it are folks with PhDs in particle-optical-physics with ten years of post doc experience working in the electron microscope field.
I really hate hearing people say stuff like this. Science isn't magic with scary, unknowable stuff going on behind the curtain. It's *very often* easily understood (car analogies, anyone? Hit me!!!111one :-). The devil's in the details and the details can be subtle, but it's not magic.
SEM bombards stuff with $something (energized particles, radiation, ...) which reflects back onto something that stores that reflected $something. It's the same process as an optical camera, but working at different wavel
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You are talking about Scanning Electron Microscopes (SEM), which do work like optical microscopes, bouncing an electron beam off of the object being imaged.
The summary is talking about Transmission Electron Microscopes (TEM), which pass an electron beam through the object being imaged, and works more like microfilm.
Re:Does anyone understand it? (Score:4, Interesting)
This is transmission electron microscopy (not SEM), where electrons are shot through the sample. It's kind of like a standard light microscope where the light goes through the sample and you see the shadow.
What they're doing is reconstructing an image from diffraction patterns instead of focusing it with a lens. I think it's vaguely similar to interferometry. They can apparently also do it with light microscopes, which has certain advantages. Unfortunately the article mixes up the electron and light microscopy - you don't do TEM on living cells, for example, no matter how fancy an imaging system you have.
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I'm having a difficult time understanding TFS's "... after they have passed through the sample using computers."
TEM is like an X-ray. You shine the "light" through and look at what comes out the other side. Shine a bright flashlight into your palm and notice that you see the light (filtered to be red) coming out the other side, with shadows for your bones and thick parts.
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TEM is like an X-ray.
Thanks, all of you guys/people. "TEM" is something I'd never heard of before.
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People should read more about science and how it's done. It wouldn't be as scary to them if they did
True, people should read more about science
Just that the TFA is not only short on detail, and the info they carry kinda not sound right
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Science isn't magic with scary, unknowable stuff going on behind the curtain
He's angered the science gods. Get him.
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Seriously, how can this piece of ignorant rant be mod as insightful?
Compare it to any random AC rant, dick!@#$. YOU ARE SO BLOODY BORING! At least TRY to contribute something of ANY value. Gahd!
I'd rather be watching Serenity than reading your puerile pap BS anyday. Go play on MySpace if you've nothing better to do, FFS.
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from TFA:
The new method, called electron ptychography, dispenses with the lens and instead forms the image by reconstructing the scattered electron-waves after they have passed through the sample using computers.
Professor Rodenburg added: "We measure diffraction patterns rather than images. What we record is equivalent to the strength of the electron, X-ray or light waves which have been scattered by the object – this is called their intensity. However, to make an image, we need to know when the peaks and troughs of the waves arrive at the detector – this is called their phase.
"The key breakthrough has been to develop a way to calculate the phase of the waves from their intensity alone. Once we have this, we can work out backwards what the waves were scattered from: that is, we can form an aberration-free image of the object, which is much better than can be achieved with a normal lens.
I call it BS, there is no other way to measure phase than by interference. It seems they just reinvented holography indeed!
Re:holography? (Score:5, Insightful)
I call BS on the summary. It says "The process has no fundamental experimental boundaries and it is thought it will transform sub-atomic scale transmission imaging". But TFA actually states "A typical electron or X-ray microscope image is about one hundred times more blurred than the theoretical limit defined by the wavelength. In this project, the eventual aim is to get the best-ever pictures of individual atoms in any structure seen within a three-dimensional object."
If they're measuring the wave diffraction as it passes through the atomic structure, then the diffraction limit is most definitely a "fundamental...boundary". If the addition of the word "experimental" means that they found no boundaries in their experiments, that just means they haven't gotten to the diffraction limit of the atomic aperture for those wavelengths yet (i.e. we're not even close to the fundamental boundaries, so we'll say our results are not limited in any way in our experiments). Either way, not a great way to talk about the results - too much sensationalism, not enough science.
Re:holography? (Score:5, Informative)
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And in turn, interference results in intensity differences arranged spatially. Thus, phase calculated from measured intensity.
It is certainly RELATED to holography.
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Yes, there is. You can measure the phase directly if the frequency is low enough. But the usual way, certainly with higher frequencies, is interference. Which is exactly what he describes - calculating the phase of the waves from their intensity alone.
From the article it sounds like they arrange for multiple diffraction images to interfere with each other.
The Lytro of TEM (Score:2, Insightful)
Expect all sorts of imaging systems to evolve in this direction over the next few years.
It's more interesting for things like CAT and NMR, IMHO.
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It's more interesting for things like CAT and NMR, IMHO.
Tricorders?
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nMR is already an interferometric process. I'm not sure how you'd use this in a CT scanner, or why.
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As to how this IS used in a research CT scanners google "phase-constrast CT". O and you want to do this in future to reduce patient dose or highlight soft-tissue boundar
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You're right, MRI (or nMRI) is nMR (Imaging). But the first poster said nMR and I wasn't feeling pedantic enough to contradict him. I really don't see how you'd use this at all if you weren't imaging.
In MRI you create an image by manipulating the relative phase of atomic nuclei with net magnetic moments. You measure the resulting interference for a bunch of different relative phases, then Fourier transform to get an image. It's interferometric imaging, except you're manipulating the phase instead of the
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I wasn't aware they did interferometric CT at synchrotrons. Cool.
Phase encoding spatial information, interferometry, different words, but they mean the same thing. You are literally measuring interference, thus interfer-ometry. The only distinction is that in MR you get to manipulate the source, which is a little harder in astronomy.
About ten years ago there were some quite enthusiastic researchers who were trying to do super-resolution MRI. Some thought it was the best thing since phase encoding, other
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Interesting now all the very different imaging modalities have vastly different implementation rates for similar techniques. Whilst the method and technology of acquis
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"Whilst the method and technology of acquisition is responsible for some of this I suspect a lot of it is researchers simply not knowing what is going on in other fields."
Yes... but adding to that, I think a lot of researchers are so tied up in their own terminology (like phase encoding spatial information) that they have trouble recognizing the same or similar processes described in other fields. I had never thought of MRI as interferometry until I had to look into it. Now when I teach it to graduate stu
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Yes I did wonder about double slit experiments (started in Atomic physics) but more so about the pattern's mere existence for single photons. The question of its shape seems trivial by comparison.
Re:It's very easy with a system of computers (Score:4, Funny)
So, are you predicting some sort of coal-mine gap?
Current users (Score:4, Funny)
The Human League, Def Leppard, Heaven 17, ABC, Cabaret Voltaire and Pulp rejoice!
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I worked at Batchelors foods with Steve Singleton from ABC before they made it big. He saved me from being beaten up by the resident bully. It's a funny ole' world :-).
Jeremy.
The most important question: (Score:5, Funny)
Re:The most important question: (Score:5, Funny)
Exactly as it's spelled.
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Re:The most important question: (Score:4, Informative)
The Sheffield that's pronounced "sheffield" is actually in Yorkshire, pronounced "yorkshire", which is where this research took place.
The Sheffield you're thinking of is the one that's pronounced "glasgow", and even there, you're more likely to run into Scots (a dialect of English, ye ken) than Scottish Gaelic, which is more of a highland thing.
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Re:The most important question: (Score:4, Funny)
>> How do you pronounce "ptychography"??
Choke on a crouton
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My guess is that the 'p' is silent so it would be something like:
tie kog rafy
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like pterodactyl?
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We're so used to ignoring things that look like ads or links to other stories that we fail to notice the images down the column at the right are, in fact, the images we're looking for.
5 times improvement? (Score:2)
Not to mention simpler preparation of samples.
To cap it off, I would expect that electron microscopy just got a whole bunch more accessible.
Well done - there might be a Nobel in it for you.
myke
The actual article (Score:5, Informative)
The actual article (Score:2, Informative)
Ptychography: great method, not new (Score:5, Informative)
The article implies that the method is new, which is not the case - in fact it even has its wikipedia page (http://en.wikipedia.org/wiki/Ptychography). The team (J. Rodenburg's) behind that press release is indeed among the pioneers.
The whole idea behind the technique is to illuminate the sample at different positions using an electron or X-ray beam, with an overlap between the different positions of the beam. Once this is done the algorithm reconstructs both the structure in the sample (the electronic density) and the structure of the probe (the electron or X-ray beam).
For those who can access articles behind paywalls :
[1] W. Hoppe, Ultramicroscopy 10 (1982) 187–198. http://dx.doi.org/10.1016/0304-3991(82)90038-9 [doi.org]
[2] B.C. McCallum, J.M. Rodenburg, Ultramicroscopy 52 (1993) 85–99. http://dx.doi.org/10.1016/0304-3991(93)90024-R [doi.org]
[3] P.D. Nellist, B.C. McCallum, J.M. Rodenburg, Nature 374 (1995) 630–632. http://dx.doi.org/10.1038/374630a0 [doi.org]
[4] P.D. Nellist, J.M. Rodenburg, Acta Crystallogr A Found Crystallogr 54 (1998) 49–60. http://dx.doi.org/10.1107/S0108767397010490 [doi.org]
[5] T. Plamann, J.M. Rodenburg, Acta Crystallogr A Found Crystallogr 54 (1998) 61–73. http://dx.doi.org/10.1107/S0108767397010507 [doi.org]
[6] J.M. Rodenburg, H.M.L. Faulkner, Appl. Phys. Lett. 85 (2004) 4795. http://dx.doi.org/http://link.aip.org/link/APPLAB/v85/i20/p4795/s1&Agg=doi [doi.org]
It's also used with X-rays (the last article is open access) :
[1] J.M. Rodenburg, A.C. Hurst, A.G. Cullis, B.R. Dobson, F. Pfeiffer, O. Bunk, C. David, K. Jefimovs, I. Johnson, Phys. Rev. Lett. 98 (2007) 034801. http://dx.doi.org/10.1103/PhysRevLett.98.034801 [doi.org]
[2] P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, F. Pfeiffer, Science 321 (2008) 379–382. http://dx.doi.org/10.1126/science.1158573 [doi.org]
[3] M. Dierolf, A. Menzel, P. Thibault, P. Schneider, C.M. Kewish, R. Wepf, O. Bunk, F. Pfeiffer, Nature 467 (2010) 436–439. http://dx.doi.org/10.1038/nature09419 [doi.org]
[4] C.M. Kewish, P. Thibault, M. Dierolf, O. Bunk, A. Menzel, J. Vila-Comamala, K. Jefimovs, F. Pfeiffer, New J. Phys. 110 (2010) 325–329. http://dx.doi.org/10.1016/j.ultramic.2010.01.004 [doi.org]
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No, it's a diffraction imaging technique. A CT scan reconstructs internal structure based on rotating a source around an entire sample. This constructs a regular image, but without the need for a lens.
I love new technology but... (Score:1)
original article (Score:4, Interesting)
took me forever to find it, but here is the original article behind the Nature paywall
http://www.nature.com/ncomms/journal/v3/n3/full/ncomms1733.html [nature.com]
the paper feels like it written by the marketing department for his company.
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After reading the paper, they are definitely doing something novel, but the claims made in the paper far exceed what is being presented. Imaging bacteria cells is considered pretty easy -- show me some atoms.
Finally!!! (Score:2)
We will be able to see that violin you talk about!!!!
Nice but not that nice (Score:5, Insightful)
They even wrote this: "The technique is applicable to microscopes using any type of wave and has other key advantages over conventional methods. For example, when used with visible light, the new technology forms a type of image that means scientists can see living cells very clearly without the need to stain them, a process which usually kills the cells."
Em, yes but optical phase-contrast is damn well established. O and Frits Zernike who got the Nobel prize for doing exactly this in 1953 might be pissed off.
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I'll say. I've got optical phase-contrast technology in 4 of the 9 cameras currently in my house.
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Well, this and most comments here seem to show that Slashdotters generally think that they understand something and then dismiss it as trivial (hint: most of the comments here completely missed the point). Ptychography generates images from the coherent scattering pattern of the object, and thus it requires no optics. The achievable resolution is limited not by the quality of the optical components, but by the wavelength of the radiation being used (and the time you are able to spend counting those electron
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O and Frits Zernike who got the Nobel prize for doing exactly this in 1953 might be pissed off.
I don't think he cares. He died in 1966.
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I don't think it's quite that simple. Their technique uses a type of interferometry to reconstruct the image - the imaging itself is done in the Fourier domain, which is definitely not the case for a phase contrast microscope. They also don't need lenses, also not the case in phase contrast microscopy.
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As such if the sample was a plane normal to the electron beam they would see nothing in this method. The imaging is not done in the Fourier domain thou the reconstruction can be if you prefer. For t
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"It's not a type of interferometry as they don't measure phase-shifts directly."
Interferometry is traditionally done by looking at interference patterns (which is what a diffraction pattern is). That's why it's called interferometry. It's only quite recently that we've been able to (sort of) measure the phase of light at reasonably high frequencies.
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See: http://en.wikipedia.org/wiki/Interferometry [wikipedia.org]
Such interferometers (which normally use a point detector and therefore aren't measuring a pattern) have been about for well over a hundred years
See: A. Michelson, E. Morley. American Journal of Science: 333–345. (188
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I should have been more clear. There are several different types of interferometry. The one you're referring to measures the relative phase between a reference beam and a beam that's had something done to it (passing through a substance or travelling a different distance). Michelson and Morley, as you point out, is probably the most famous example. They were measuring (or trying to measure) very small differences in the time it took two light beams to travel the same distance, in different directions.
A
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Indirectly by observing the imaging pattern (like a classic optical fringe pattern) the phase-shift can be done. Thou you might have to manipulate the beams to make the pattern more obvious as in classic interferometers or classic phase-contrast microscopy. Or you can
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I'm not sure if you think I'm wrong or you think I'm right but misunderstood what I said. I do not think it's possible, at this time, to directly (i.e. without causing two signals to interfere with each other) measure the phase of high frequency waves, EM or electron. IIRC people are starting to talk about doing direct phase measurement (sort of) with infrared. If you do think it's possible, and know of an example, I would be very interested to read about it.
The Sheffield people aren't measuring the phas
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IMHO they are exactly doing a classic optic phase-constrast technique. Not exactly the same geometry as in microscopes due to the vastly superior optical beam available. But very similar and identical to the one often used for accelators X-ray CT which is why they reference this research. If you think this is wrong thats fine, I just disagree.
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O and if you actually read the paper you'll see that on the right hand column of page 5 all the current experimental limitations on resolution are listed. That the lens doesn't feature doesn't mean it follows that it is just down to wavelength, it's not. There is no lens in any hospital X-ray systems and your 100 keV diagnostic X-rays does not give you ~0.01nm resolution images. There is
Coming soon to a TSA booth near you! (Score:2)
We want to see your electron clouds
Goody Goody Gumdrops! I want one! (Score:2)
Of course, who wouldn't? Looks like a lot of fun, not to mention we might have some scientists in some fields make some discoveries. If we have any scientists, do we still do that or did we outsource?
So the flow is... (Score:1)
So while the old way had the electrons go through a "lens", they now go through a "computer."
I have this vision in my head of people looking through PC chassis and hoping to use it in place of a lens. So, what type
TEMs in the 1980's... (Score:2)
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Data recovery? (Score:2)
Given electron microscopes are already used for data recovery of mission critical hard drives, it makes me wonder if this discovery has any effect on DOD drive wiping standards.