Physicists Extend Moore's Law For Tiny Devices
schliz writes to mention that a team of quantum physicists have demonstrated how to significantly reduce the effects of "stiction," or the tendency for two very small, very close objects to stick together as a result of Casimir force. "'The Casimir force might be one of the many reasons that very small, movable components in micromechanical devices sometimes stick together,' said Ho Bun Chan, a assistant professor of physics at the University of Florida who is researching the Casimir force. 'The Casimir effect increases rapidly as the separation between components decreases. It becomes significant when the separation is reduced to below about 400 nm,' he told iTnews."
Now if only we could use it as a power source....I would LOVE a ZPM ala Stargate!
I always wondered why stuff always sticks to one of my sweaters..
I work for the Department of Redundancy Department.
We've already reduced and even reversed casmier effects, haven't we..?
Or is this different somehow?
We dodged a real bullet there, I tell ya! I mean, had they not enacted this extension when they did, we would have been stuck. And I mean STUCK with the large devices are forced to use now.
I think Casmir should be taken out behind the tool shed and whipped for his bad behavior.
Bearded Dragon
The Casimir effect is very wierd indeed. If you take two metal plates and put them close together in a vacuum they will attract one another VERY weakly. The effect is caused by fluctuations in the electric charge of the vacuum. Think of it a little like sea level. On average if you measure sea level lots of times you wil get "0" for the height but if you measure it just once the height you get will depend on the tide and the size of any waves. The same is true for a vacuum. Look at a particular volume of space and measure the electric charge. On average you will get zero but for a particular moment in time it may be non-zero.
Ok so far but how do we get an attractive force? Well it turns out that charge must be conserved so if one region of space has a small positive charge at one instant a neighbouring area must have a small negative charge (in quantum terms we say that we pair produce and virtual electron-positron pair) thuse we have a dipole. Now remember the two conductors? Well the one nearest the positive charge will have the electrons in the conductor attracted to it and being a conductor they will move towards it giving the conductor a net negative charge. The opposite will happen in the conductor nearest the negative charged area of space.
So now we have, instantaneously, a conductor with a negative charge and one with a positive charge...so they attract one another. this is the Casimir effect. If you stop to think about it is is VERY strange because it means that two metal plates in vacuum, with no externally applied fields will attract...so you have to ask yourself what exactly is doing the work i.e. where is the energy coming from to move these plates?
I'm not a condensed matter guy so I must admit I don't quite understand why this effect is so important to them. I understood that in molecules it was known as Van der Waal forces and due to periodic dipoles occuring in molecules in much the same way it does ina vacuum. Only, because there is a real electric field, the effect is much larger. So if there are any condensed matter people out there perhaps they would like to explain why it is Casimir and not Van der Waals that is important? or is it just because they have the same origin the name Van Der Waals has been dropped?
Moore's Law has nothing to do with mechanical components. For that matter, strictly speaking, all Moore's Law was ever about was the number of components in an IC. Not speed, not cost, not even size. And definitely not the size of MEMS!
The stiction effect has been an issue for many years in the disk drive world. The heads in a HDD are planar against a disk that is also a polished planar surface. The net effect is to require amps of current (briefly) when spinning a disk drive up.
After coming up to speed, there is an air bearing between the two, as the head float on a cushion of air. This effect has been an issue in the HDD world for over 30 years.
www.effectiveelectrons.com "chips that work" Analog, RF, Mixed Signal
And for those of us who couldn't remember which online enclycopedia is a good, free place to look up terms we aren't sure of: http://en.wikipedia.org/wiki/Wikipedia.
:)
Just in case.
You know, just in case somoene forgot.
Forgot about wikipedia, I mean.
Because, apparently, looking something up on wikipedia is esoteric enough that a post with a link to wikipedia (and nothin else!) is informative.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
The other two replies are correct, but let me give a little more detail - the casimir force is very short-range, and essentially goes to zero over the distance of a micron. The corrugations in the surface are micron-deep trenches, and so the extra surface area is essentially hidden.
Okay, that's not a terrible summary, but for more details about this experiment and its importance, you can look at http://physics.aps.org/articles/v1/4 which also cites the actual article.