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Build Your Own Scanning Tunneling Microscope
I don't want to spen writes "For all you fans of nanotech out there, a friend just posted me a link to instructions for building a scanning tunnelling microscope, from the University of Muenster. Interestingly, their licensing terms sound open source-ish to me: '(... We grant everybody the right to construct the microscope using the here-published design for private or educational purposes. On these web pages all necessary diagrams, drawings, material descriptions and software-source-codes are published for free access. While granting the right to build the microscope we make it mandatory that new developments, improvements or other applications of our design are also made openly available for private or educational purposes...)'"
come on! At least write it in java....
:-D
Seriously though, looks like a great summer project.. Not to mention my college will now have a SEM because of these plans
Okay the instructions are in English - nice. The diagrams are in German? Need a little help here...
A hardware desging, in the GPL style, released to man for his education and enlightenment?
/faints/
You mean this is not like, say for a example, some greedy physician who comes up with a slightly different way of suturing someone with existing tools, patenting said technique, and then demanding worldwide royalties????
The end is near!
--
Well, I still have this covered, but not many of my friends do.
I'm an American. I love this country and the freedoms that we used to have.
Interestingly, their licensing terms sound open source-ish to me: '(
:'("
heh, did anyone else quickly glance at that and think he was making a sad crying face because it sounded open source?
"Uh oh! It sounds like open source!
Atomic force microsopes on the other hand can do some very neat work with small organic particals, but seperating something like an HIV from solution is still difficult, and usually involved crystalization.
How we know is more important than what we know.
I dont think so
;-)
With BSD or GPL style licenses you are actually allowed to use the copyrighted work in an commercial setting, just not to sell it. For instance a commercial company might run their web server using GPL licensed software.
With this not only do they retain the exclusive commercial rights, but the license might in fact be read as an attempt to force you to turn over any improvements on their design.
So if you make an improvement, does this mean that you have implicitely granted the University of Muenster the rights for commercial exploitation of your own improvment by accepting their license in the first place?
This does not sound "open source-ish" to me, it sounds like out right theft.
PS: Please ignore any bad spellings/grammar in my english or at least be polite when telling me
This type of microscope requires a target which will conduct electricity. That's why images are typically of gold, semiconductors or items which have been electro-plated.
Your comment makes little sense. My lab does a lot of microscopy. B & L strictly make optical microscopes, which by the wavelengths of light, and properties of glass are restricted to resolve objects down to about 100 nanometers or so (at best - and we're talking with a really really good confocal or deconvolution microscope that runs about $500K). Mediocre electron microscopes visualize objects down to about 1000 angstroms. That's two orders of magnitude better, perhaps more if you have a good EM setup.
See if those penis enlargement pills are working.
I am not aware of any of any instance of a large molecule whose structure was deduced from a scanning tunneling microscope. Things like proteins, enzymes, and viral particles are most generally probed by growing them into crystals and a analyzing their x-ray diffraction patterns. The big problem with this technique is that big molecules are hard o grow into crystals (thus all the grow protein crystals in the micro gravity of orbit effort) Nonetheless, a Scanning tunneling microscope is VERY COOL, and within the engineering capabilities of a dedicated hobbyist. Heck, you can now buy a complete Scanning tunneling microscopes for 20K; pretty cheap for a high-end piece of laboratory equipment. The real trick is to get the stage into a hard vacuum at cryogenic temperatures. Who will be the first person to spell out LINUX in Xenon atoms on a nickel substrate? I will donate money to that cause By the way, in college I used to produce atomically sharp needles for field emission ion sources just by burning tungsten wire in a propane torch. That should be an easy way to make probe tips
I mean this is cool, bet really the cost on older electron microscopes is pretty low (under 2k) Heck theres a phillips 500 for sale on Ebay for $1000 right now. I've often thought about buying one, but dont have 3 phase in the house and the garage is a little damp.
Yes, his post is completely wrong. However, there have been advances in STM so that you can do STM with fixed organic samples now. Here's an example of a recent published study. Also atomic force microscopy (AFM) has become fairly common with fixed organic samples. I'm not calling you wrong - I'm just updating Slashdot readers to the state of the art in biological microscopy.
Depends on the size of the protein, but unfortunately you're right for most interesting proteins. There are hybrid computational modelling + mass spectrography techniques that can reduce the required computational time by orders of magnatude. When peptides fold up into proteins they make covalent bonds between the aminoacids. When you're doing a computer simulation you can say something about which bonds are more likely than others (and this can reduce your run time to less than blind search) but you can't say with any certainty which aminoacids are bound to which. What these hybrid techniques do is cut up the folded protein into small molecules (5-6 aminoacids) and then messure the mass. From this data you can tell if there are certain crosschain combinations. For example, you can see that there is a Cysteine-Asparagine bond and if there is a Serine-Proline bond or whatever. Armed with this information you can remove a lot of possibilities from your search space.
How we know is more important than what we know.
Unless they have patents, there is nothing they can do to stop someone from building a microscope using their plans. The only thing they can do is stop you from copying the plans themselves (under copyright law).
John D. Alexander, the inventor of the disk scanner, also has a 'free' STM design on the web. Incidentally, this guy took out a patent on the disk scanner, then withdrew the patent application! Now that's a smart way to make sure others cannot lock up a design with patents (or he just ran out of money).
Talk about a classic example of looking a gift horse in the mouth.
You're getting this information for FREE. It hurts you not at all to have such a 'stupid' license, because previously, you didn't have the information at all. By every imaginable definition of the concept, you have more available to you now than you did previously.
You have no justification for being so bitter. In this era of jealously defended "intellectual property", ANYONE giving anything away deserves commendation.. not derision.
Despite what they call it in English (University of Muenster), the proper name is the Westfaelische Wilhelms Universitaet. Even though I am an American, I studied there for a semester.
/., it isn't a surprise to see good things from Muenster. It is one of those wonderful little secrets - a top notch place few know about.
;)
Muenster is a wonderful college town, as well as a place of historical significance (30 years war ended there). The hospital associated with the university, and thus the medical program, are well respected across Europe. (Comparible to Mayo / Johns Hopkins / Mass. General here in the US).
Anyway, while it is surprising to see this on the front of
Posting AC because I believe in privacy on the net
The GPL only kicks in when you *distribute* copies of the software. In this case if you choose to ignore the GPL, copyright law defaults to 'you are not allowed to distribute the software'. Hence the *only* legal way to distribute (note: I didn't say 'use') GPL'd software is to agree to the GPL.
There is a similar reasonably well-documented homebrew STM that was built by a guy named Jurgen Muller. His site is pretty interesting, and well worth the read.
Obviously there are a lot of articles on STMs in various academic journals. If you're at a university, you might start by searching in Reviews of Scientific Instruments and perhaps the Phys Rev journals.
I was involved with a STM project for a while, and our conclusion was that the 3D piezo setup is quite fragile, and extremely difficult to isolate from vibration, etc. It seemed that a better design was a so-called slip-stick walker, which uses a stage that slides on smooth rails. A tube of piezoelectric ceramic is attached and driven in such a way that it creates a series of small, sharp forces on the stage that momentarily break the static friction between the stage and base, causing it to move in small steps.
This stage is used to approach the sample to the STM tip, which is mounted on another piezo tube, and can be deflected laterally and vertically in order to do a raster scan of a small area of the surface.
The limitation to this method is that you can't scan a very large surface area. You can add a second "walker" unit underneath the first one so that you can move the sample from side to side in addition to moving it towards/away from the tip, so this would allow you to scan a stripe across the surface.
To get full 3D control, there are several designs called "beetles" (IIRC) that are described in the literature, which use a somewhat similar technique that allows more control.
We assure you, however, that hanging the scope from a thin scaffolding using light springs, and then attaching the entire setup to a huge piece of granite will not be sufficient.
On a more serious note, an STM is really easy to build, but really hard to make work. There has been more than one physics graduate student that has entered perpetual grad school limbo trying to get one of these to work. The vibration damping is just the start. Learning to etch the tungsten probes so that you get the necessary few atoms at the end is quite an ordeal. And then attaching the probe without allowing the tip to even come close to any surface. And then calibrating the piezoelectric so that the tip will be very very very close to the sample, but never touch it. You will go through 100 hand etched probes before the instrument is even grossly calibrated.
And then measuring the gap current. You learn what kind of noise a power supply really has. Getting a noise low enough so that a signal is discernible after amplification requires a power supply the likes of which few has seen. And then the noise that introduced by the amplification process. This are not your ordinary op amps. I shudder to even think about building a board that quiet.
But have fun, and remember us for you optical table needs. We are, after all, the only one who sell the genuine and otherwise real and purchasable Vibration Proof Table(TM)(patent pending).
"She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
For a horrible, horrible moment, I read the headline as "Build Your Own Spamming Tunneling Microscope."
Just think what horrid new forms of viral marketing a research tool like that could help develop.
I am probably quite qualified to answer your
question seeing as I do STM research for a living.
Your second question is easier to answer, so I'll
do that first:
there are two ways, either you put down enough
of them to assure there will be a molecule in the
range of your scanner whereever you approach
or you use some other technique like lithography
to make small structures then another technique
to deposit your molecules near those structures
then (if you got the microscope that allows it)
position your tip optically near the structure
and spend days on looking around with STM until
you find it.
Now you first question. STM can be used to find
some structural info from large molecules. My lab
has done some research on nanotubes and you can
get atomic resolution on those and then determine
their helicity. People have also imaged bio stuff
and for some smaller molecules have seen the
structure. Even DNA has been imaged. That said,
STM is not a great structure probe, it is a great
probe of electronic states.
Last word of warning: people rarely realize that
STM in air is not going to tell you anything
that you can rely on physics-wise. The reason is
that all surfaces exposed to air are covered in a
thin layer of water which makes the interpretation
of data hard. What they show on that page is a toy
though well-thought-out and maybe even useful to
some. Seeing atomic steps on gold and "atomic"
resolution on HOPG is not hard, just don't hold
your breath for something like atomic resolution
on gold, or silicon, or anything else really.
For that you at least need a UHV system.
Cheers.