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Speeding Up STM Imaging 44

Posted by kdawson
from the ready-for-my-close-up-mr.-demille dept.
Roland Piquepaille writes "Probably not many of you have used a scanning tunneling microscope (STM), the essential tool of nanoscience. And you might think that it's as easy to take a picture of an atom with an STM as it is to take a shot with your digital camera. In fact, the imaging of individual atoms with an STM is quite slow. Now researchers at Cornell University have shown how to accelerate this process — by adding a radio transmitter, they are able to speed up atomic-level microscopy by a factor of at least 100. A typical STM currently has a sampling rate of about one KHz. This new radio-frequency STM can operate a thousand times faster."
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Speeding Up STM Imaging

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  • Building a STM (Score:5, Interesting)

    by Aglassis (10161) on Monday November 12, 2007 @06:31AM (#21321385)
    Probably not many of you have used a scanning tunneling microscope (STM), the essential tool of nanoscience

    You might be surprised [slashdot.org].
    • Re:Building a STM (Score:5, Insightful)

      by Potor (658520) <.farker1. .at. .gmail.com.> on Monday November 12, 2007 @07:48AM (#21321741) Journal

      And you might think that it's as easy to take a picture of an atom with an STM as it is to take a shot with your digital camera.
      has a dumberer sentence ever been uttered in a /. submission?
      • by jamesh (87723) on Monday November 12, 2007 @08:11AM (#21321855)

        And you might think that it's as easy to take a picture of an atom with an STM as it is to take a shot with your digital camera.

        has a dumberer sentence ever been uttered in a /. submission?

        I don't think so. The last picture I took with my digital camera had billions of atoms captured. If an STM can only capture a few at a time then it has a lot of catching up to do!
      • by niceone (992278) *
        has a dumberer sentence ever been uttered in a /. submission?

        I'm not sure, there are plenty of candidates. Leaving that aside, I think you have invented the perfect word for the sequel to "Dumb and Dumber", they can call it: "Dumber and Dumberer" :-)
      • by frieko (855745)
        You must be new here. Roland's submissions always make the front page regardless of how dumberer/non-newsworthy they are.
  • by Anonymous Coward

    Probably not many of you have used a scanning tunneling microscope (STM), the essential tool of nanoscience
    Wow, this guy must be psychic!
    • by ParaShoot (992496) on Monday November 12, 2007 @06:40AM (#21321437)

      Wow, this guy must be psychotic!
      Fixed.
    • And yet, others of us, have use them. Pretty common on Universities. In general, most advanced degreed biologists will have had a class in it, so will most biochemists. In addition, a number of Physicists and Engineers will most likely have played with them.
      • Wow, I'm familiar with the STM (I have never used one) but I am not familiar with many people have access or use for one. I thought they were used most for more basic surface physics type of work. Perhaps you are thinking of an SEM or STEM which are now quite common (especially the SEM) and used in a variety of fields? If not, what general use does the STM provide for biology?
  • Now researchers at Cornell University have shown how to accelerate this process -- by adding a radio transmitter, they are able to speed up atomic-level microscopy by a factor of at least 100. A typical STM currently has a sampling rate of about one KHz. This new radio-frequency STM can operate a thousand times faster.
    .. but isn't one KHz already pretty fast. I mean, I can't take pictures with my digital camera that fast... more like 0.5Hz.
    • by prefect42 (141309)
      Depends what the target of the performance measure is. To stick with your camera, if it's 0.5 pictures a second then that's fine, but if it's 0.5 pixels per second...
    • by IWannaBeAnAC (653701) on Monday November 12, 2007 @08:55AM (#21322065)
      In an STM machine, there is a single tip that moves over the sample. The sampling is done one pixel at a time, in much the same fashion as the beam of a CRT for example. So 1kHz is rather slow; for your 3 megapixel digital camera it works out at 3000 seconds (almost 1 hour) per frame. So a 1000x increase in speed is really significant!
  • Wait a bit (Score:2, Funny)

    by AlphaLop (930759)
    Don't buy one now though, because a model with double the features will be out in 6 months for less $$$ ;)
  • you mean like... one megahertz?
  • by Anonymous Coward
    I thought the limiting factor of SPMs (including STMs) is the feedback loop: one has to keep the probe tip from crashing into the surface as it's dragged back and forth, which means that the scan has to be slow enough that the piezo stack that's moving the probe tip up and down can do its job (limited by speed of sound through the material), as well as the electronics that have to decide how to move the thing in the first place. This might help with the electronics, but 1000x speedup in sampling rate doesn
    • by ndg123 (801212) on Monday November 12, 2007 @07:26AM (#21321647)
      On atomically flat surfaces with small scan areas, you can scan in constant height mode (rather than constant current, where the tunneling current is the input to the feedback loop to adjust the probe height ). Still, a 400x400 point image of a 20 x 20 nm area still used to take a couple of minutes. Not 1/1000 second.
    • Re: (Score:3, Informative)

      by jibster (223164)
      The speed a piezo stack responds is related to the speed of sound but not in the way you think.

      Each active element of the piezo receives the electrical signal to expand\contract at the speed of electricity through the material. This is usually very close to the speed of light. So the entire stack basically gets the signal move in parallel.

      At that point we require a mechanical movement but since we are typically asking it to change by about 1nm/s this doesn't take a long time to do.

      One day the response tim
  • So.. is the speedup 100 or 1000?
  • Fabulous STM photos (Score:5, Interesting)

    by ribuck (943217) on Monday November 12, 2007 @07:43AM (#21321721) Homepage
    If you want to see photos of atoms taken by an STM, there's a great gallery here:

    STM Image Gallery
    http://www.almaden.ibm.com/vis/stm/gallery.html [ibm.com]
  • Huh? (Score:3, Interesting)

    by Pseudonym (62607) on Monday November 12, 2007 @07:57AM (#21321789)

    Essential? Bah! I work in a nanotech lab, and we don't have a STM!

    We do have a brand new AFM [wikipedia.org], though, and it is kinda sluggish. I wonder if this technique would speed up that.

    • Re: (Score:1, Informative)

      by Anonymous Coward
      AFMs are SPMs, as are STMs. But AFMs work on the principle of van der Waals forces, not electrical current, so this wouldn't apply to them. Most AFMs on the market today are actually general-purpose SPMs that can work in AFM mode, with a plethora of optional modes (including STM... you can find an incomplete list of modes here http://en.wikipedia.org/wiki/Scanning_probe_microscopy [wikipedia.org].
    • The fact that an STM sample [generally] must be conductive may make it more limited in applicability vs AFM, but if you are trying to get, for example, *true atomic resolution under ambient conditions*, STM is still the only way to go.
  • When I was in high school in the Soviet Union around 1992 a friend of mine built one. He used a regular broken sewing needle for the tip, the idea was that when you break a needle the resulting surface is not smooth and there are bumps with a single atom on top.
  • So will this device allow us to observe viruses in real time? so instead of finding cures for specific viruses that do not work on the next mutation, we could find how viruses operate on atom level and find a cure for that level...much like doing debugging in assembly language.
  • STMs can be used to push together atoms into molecules. If they can get the access time down, and the seek time, put it into a cheap USB enclosure, then I'll take one.
  • Pardon my ignorance, but I also assume that I am in the vast group of /. readers who have no idea what difference the scan rate will make in actual scientific research. I don't really care about how scan tips are made, most of the humor attempts seem flat, and through it all I am asking myself "faster speed must equal ability to do more science, but what's in it for the rest of the world other than a curious factoid. It's kinda like the research that shows that in certain weird cases, scientists are able t
    • Your question is similar to "What's the use of a telescope? All it does is make things look bigger! It doesn't have any effect on real life."

      Galileo used one of the first telescopes to see that Jupiter is a planet with it's own orbiting moons. Again, that was just a bit of trivia to the common man in his day. But a few centuries later we're using that knowledge to send spacecraft around the solar system.

      A new scientific measurement technique is first used to explore fundamental physics and acquire basic
    • STMs and AFMs are important because they let us see things much smaller than conventional optical microscopes can. Increasing the scan rate by a factor of 1000 might yield new applications, taking better STM movies, and elucidating mechanisms that run that much faster.

      The only public data released on the RF STM stuff seems to be this one lonely chart [kschwabresearch.com]. The gamma variable (on the Y axis) has to do with electrical reflections that come about because of impedance mismatches on transmission lines. For more in

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