Oh yeah... one more thing...
I have a video of some Maglev on my website, A little info about it: It's room temp, There is zero energy input and it's stable.. Just watch it.
Cool...
Yeah... our record is not quite 10^-12, we've had 1.2 x 10^-11 before, which is damn good. I think we can get 10^-12 if we don't open the cambre for a long time and leave the I-Pump running full cycles.
The maglev is because it's about all we can do in Lethbridge. Our lab is in a shitty part of campus (can't get better, no room). We are basically a big frickin concrete antenna. I don't know if you've ever seen pictures of our world-famous architecture, but it's hella bad for vibrations. We use a biscuit to cut alot of the noise and try our best to shield outside noise as well, but We can barely get atomic resolution without more Vibration isolation. As for maglev... you called it! It is a bitch to get working, but the experiments I want to run require unprecidented resolution. this can only be done by Low temp and and extreme vibration Isolation.
The maglev isn't working (yet) because as you said, it is a bitch. We may compromise with a combination system. I am designing a prototype system for maglev and I've achieved resonances.5 Hz with a nice Q-factor, but I just can't lift much of a payload yet. 10 grams is about all I can do. We decided maybe to use a spring to lift more mass in conjunction with maglev.
Are you an Undergraduate? Graduate? Professor?
I'd be interested in your work/papers...
Hi.. I work on an STM for my Masters, if you are interested, I have pictures of the STM and a SEM (Scanning Electron Microscope) from the lab.
(Two totally different things)
http://stevenhorn.kicks-ass.net/cpg/index.php?cat= 7
Enjoy... please don't leech them without sourcing.
Actually, temperature isn't that big of an issue. A bigger issue is mechanical vibrations. The world we live in is very very noisy. Too noisy to do STM in. These vibrations must be filtered out in an atomic-resolution microscope. There are several methods to do this including Springs and Mecanical tables. I am working on a maglev method which is highly experimental.
Temperature is somewhat of an issue still as if it gets HOT (like anything... think of melting your CPU) then the nano-structure will be lost. Even at room temperature, structures of a few dozen atoms are stable as long as the electronic structure of the surface is inert. If you have valance gaps in the surface, the temperature will result in the atoms having enough energy to jump well potentials and reassemble in a form that may not be desired.
Trick here is to plan your materials so that the surface isn't reactive, and then you should be fine even at or above room temperature!
In reality, the issue of vibrations and thermalization isn't that big a deal for nano-science. There is, however, always room for improvement.
Hope that answers your question
Re:Wot.......a new hybrid device?
on
Nanotech or Nano-Not?
·
· Score: 2, Interesting
A DVM is a high impedance device. Measuring voltage is not the same as measuring current. Theoretically, the ideal voltmeter will have ZERO amps through it. Now think about an ammeter. What is the lowest amperage you can read on a hand held ammeter? The problem should now become apparant. Also remember, 1 AMP is ALOT of electrons. It's an absolutely HUGE number! so you are right in a sense in believing that a nano amp isn't really that small.
New ammeters are now capable of measuring currents of individual electrons. blows my mind.
as for you question about building your own STM... It is definately possible, You can even do it in your basement!!! all you need is a little bit of investment $$$ and some know-how. The STM I work with was built by Undergraduate Students in the University (Which I helped with) It's almost entirely home-brew. The only part of it that is not is the control circuits, amplifiers, and the software.
However, looking at actual atoms isn't that easy. One HUGE, MONUMENTAL, CATESTROPHIC item I didn't mention was vibrations. You may not notice, but you live in a noisy world. Especially in a city. In order to see these atoms, you need the surface and tip to be very very quiet. A sound room is even too loud. There are many methods to do this including Springs and mechanical tables. I am working on a maglev method which is very experimental still.
Bottom line however.... If you want your own STM in the basement, have an extra $20,000 lying around, you have done your research... give it a shot, even if it doesn't work, you'll learn hella lots about software, hardware, drafting, and most importantly;) physics.
Re:Wot.......a new hybrid device?
on
Nanotech or Nano-Not?
·
· Score: 5, Informative
I'm a Masters student working with a UHVVTSTM that is... an Ultra High Vacuum ( 10^-12 Torr) Variable Temperature (works from 3K-300K) Scanning Tunneling Electron Microscope.
Here's a quick lesson for those of you who are a little brighter than the audience the article is targeted for. If you study Quantum Mechanics, you probually studied an effect called Barrier Tunneling, in which a particle can exist in a forbidden region in a high potential and there is the probability of measuring that particle on the other side of the barrier. This is the basis for STM. Consider the vacuum in the chamber as a barrier. Now, take a very sharp needle (Say Tungsten) that is nearly atomically sharp. Now, if you bring the tip very close to a surface (Say Silicon) then even though there is a gap between the Tungsten tip and Silicon surface, electrons orbiting atoms in the tungsten can "tunnel" across into orbits of Silicon atoms. This tunneling of electrons is what is the tunneling current and is a purely Quantum Mechanical effect.
By measuring this current (nano - pico Amps!!) and varying the gap to make the current constant, we can now move this tip over this atomic surface. My monitoring the changing current and moving the tip in or out as the tip is scanned (much like a CRT scans electrons on your TV screen) we can see an image of the electron configuration of the silicon surface! From this we can infer what the structure is.
It's reall quite neat. If course, I am not going into many details here, but if you are interested in learning more, contact me:
steven.horn at stevenhorn.kicks-ass.net
My thesis title is atomic manipulation using a scanning tunneling microscope. I study organic molecules on silicon surfaces hoping to develop new nano-devices. I also study it because it's really cool.
Slashdot Mirror
Oh yeah... one more thing... I have a video of some Maglev on my website, A little info about it: It's room temp, There is zero energy input and it's stable.. Just watch it.
Cool... Yeah... our record is not quite 10^-12, we've had 1.2 x 10^-11 before, which is damn good. I think we can get 10^-12 if we don't open the cambre for a long time and leave the I-Pump running full cycles. The maglev is because it's about all we can do in Lethbridge. Our lab is in a shitty part of campus (can't get better, no room). We are basically a big frickin concrete antenna. I don't know if you've ever seen pictures of our world-famous architecture, but it's hella bad for vibrations. We use a biscuit to cut alot of the noise and try our best to shield outside noise as well, but We can barely get atomic resolution without more Vibration isolation. As for maglev... you called it! It is a bitch to get working, but the experiments I want to run require unprecidented resolution. this can only be done by Low temp and and extreme vibration Isolation. The maglev isn't working (yet) because as you said, it is a bitch. We may compromise with a combination system. I am designing a prototype system for maglev and I've achieved resonances .5 Hz with a nice Q-factor, but I just can't lift much of a payload yet. 10 grams is about all I can do. We decided maybe to use a spring to lift more mass in conjunction with maglev.
Are you an Undergraduate? Graduate? Professor?
I'd be interested in your work/papers...
Hi.. I work on an STM for my Masters, if you are interested, I have pictures of the STM and a SEM (Scanning Electron Microscope) from the lab. (Two totally different things) http://stevenhorn.kicks-ass.net/cpg/index.php?cat= 7
Enjoy... please don't leech them without sourcing.
Actually, temperature isn't that big of an issue. A bigger issue is mechanical vibrations. The world we live in is very very noisy. Too noisy to do STM in. These vibrations must be filtered out in an atomic-resolution microscope. There are several methods to do this including Springs and Mecanical tables. I am working on a maglev method which is highly experimental. Temperature is somewhat of an issue still as if it gets HOT (like anything... think of melting your CPU) then the nano-structure will be lost. Even at room temperature, structures of a few dozen atoms are stable as long as the electronic structure of the surface is inert. If you have valance gaps in the surface, the temperature will result in the atoms having enough energy to jump well potentials and reassemble in a form that may not be desired. Trick here is to plan your materials so that the surface isn't reactive, and then you should be fine even at or above room temperature! In reality, the issue of vibrations and thermalization isn't that big a deal for nano-science. There is, however, always room for improvement. Hope that answers your question
A DVM is a high impedance device. Measuring voltage is not the same as measuring current. Theoretically, the ideal voltmeter will have ZERO amps through it. Now think about an ammeter. What is the lowest amperage you can read on a hand held ammeter? The problem should now become apparant. Also remember, 1 AMP is ALOT of electrons. It's an absolutely HUGE number! so you are right in a sense in believing that a nano amp isn't really that small. New ammeters are now capable of measuring currents of individual electrons. blows my mind. as for you question about building your own STM... It is definately possible, You can even do it in your basement!!! all you need is a little bit of investment $$$ and some know-how. The STM I work with was built by Undergraduate Students in the University (Which I helped with) It's almost entirely home-brew. The only part of it that is not is the control circuits, amplifiers, and the software. However, looking at actual atoms isn't that easy. One HUGE, MONUMENTAL, CATESTROPHIC item I didn't mention was vibrations. You may not notice, but you live in a noisy world. Especially in a city. In order to see these atoms, you need the surface and tip to be very very quiet. A sound room is even too loud. There are many methods to do this including Springs and mechanical tables. I am working on a maglev method which is very experimental still. Bottom line however.... If you want your own STM in the basement, have an extra $20,000 lying around, you have done your research... give it a shot, even if it doesn't work, you'll learn hella lots about software, hardware, drafting, and most importantly ;) physics.
I'm a Masters student working with a UHVVTSTM that is... an Ultra High Vacuum ( 10^-12 Torr) Variable Temperature (works from 3K-300K) Scanning Tunneling Electron Microscope. Here's a quick lesson for those of you who are a little brighter than the audience the article is targeted for. If you study Quantum Mechanics, you probually studied an effect called Barrier Tunneling, in which a particle can exist in a forbidden region in a high potential and there is the probability of measuring that particle on the other side of the barrier. This is the basis for STM. Consider the vacuum in the chamber as a barrier. Now, take a very sharp needle (Say Tungsten) that is nearly atomically sharp. Now, if you bring the tip very close to a surface (Say Silicon) then even though there is a gap between the Tungsten tip and Silicon surface, electrons orbiting atoms in the tungsten can "tunnel" across into orbits of Silicon atoms. This tunneling of electrons is what is the tunneling current and is a purely Quantum Mechanical effect. By measuring this current (nano - pico Amps!!) and varying the gap to make the current constant, we can now move this tip over this atomic surface. My monitoring the changing current and moving the tip in or out as the tip is scanned (much like a CRT scans electrons on your TV screen) we can see an image of the electron configuration of the silicon surface! From this we can infer what the structure is. It's reall quite neat. If course, I am not going into many details here, but if you are interested in learning more, contact me: steven.horn at stevenhorn.kicks-ass.net My thesis title is atomic manipulation using a scanning tunneling microscope. I study organic molecules on silicon surfaces hoping to develop new nano-devices. I also study it because it's really cool.