Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Science Technology

Physicists Extend Moore's Law For Tiny Devices 85

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."
This discussion has been archived. No new comments can be posted.

Physicists Extend Moore's Law For Tiny Devices

Comments Filter:
  • by clonan ( 64380 ) on Friday July 18, 2008 @01:43PM (#24245041)

    Now if only we could use it as a power source....I would LOVE a ZPM ala Stargate!

    • Zero Point Energy will never yield any significant amounts of energy. It's merely an artifact of the way the Universe is constructed, and not a large source of power or fuel. Stargate attempts to remain (somewhat) scientifically accurate by positing that a micro-universe is contained inside each of the ZPM devices, and that the device attempts to extract all energy from that universe via Zero Point Energy extraction. Thus the ZPMs are capable of "running out" of power once all the energy from the micro-universe is exhausted.

      Technically, such an idea suggests that the ZPMs should deliver a constant stream of power at all times. Yet in practice, the ZPMs shown in the program appear to behave more like batteries; often providing more or less power depending upon the city's current requirements. However, this appears to be a literary device as it creates a variety of consistency problems within the program. (e.g. If energy can be extracted at such a rate as to exhaust the unit within a few minutes, why can't the city fly on only one ZPM?)

      • It could always be that the device pulls zero point energy from the pocket universe inside, and then stores it in some kind of capacitor or battery, thus leading to a constant stream of energy being maintainable for a semi-arbitrary amount of time, but unusually high draws being only available in the short term. In which case the city *could* fly on a single ZPM, but only until the additional stored charge had been exhausted (which might be a frighteningly short time, and nonsustainable flight is usually *
        • I could buy that if it weren't for the fact that Rodney completely depleted a ZPM in only a few minutes of operation. (See: McKay and Mrs. Miller []) If the ZPM used capacitors to store a "boost" charge, then he would have been unable to completely deplete the ZPM. Either that, or the ZPM was nearly depleted anyway which means that it was about to become a paperweight anyway.

      • Re: (Score:2, Interesting)

        by Two9A ( 866100 )

        It's the difference between voltage and current. The Atlantis stardrive requires at least 10GV to fire, and the output of any given ZPM is rated at a more-or-less-constant 5GV, with DC/DC stepdowns feeding power through the city.

        (Or maybe I'm talking utter shit, it's up to you.)

      • by hr raattgift ( 249975 ) on Friday July 18, 2008 @03:27PM (#24246367)

        ZPM power production[*] is rated in the non-SI unit "Plot" (analogous to J/s, the second derivative of energy[**], and the first derivative of work[***]).

        A ZPM's normal production appears to be approximately 0.1 Plot per episode in which it is portrayed, although in some episodes a ZPM shows how powerful a device it can be, delivering just shy of a full Plot.

        The third derivative of energy, "Twist", analogous to J/s^2, can be used to analyse the output of the ZPM over the duration of an episode. In some cases the ZPM provides a substantial Twist, progressing from normal power production to zero or to explosive overload within the span of an Act.

        A high-Twist, high-Plot device is consistent with the ZPM as portrayed in Stargate SG-1.

        I never got into Stargate Atlantis, sorry.

        [*] or production power, which may be more appropriate.
        [**] Writer's energy, that is.
        [***] Professionally employed TV writer, that is.

      • The city CAN and HAS flown using just one ZPM (sure, it needed a little extra energy boost from a thermal vent power station, but let's give them a bit of a break as far as that goes - they were being fired on by ONE HELL of a energy weapon and had an entire fucking ocean on top of them at the time.).

  • by v1 ( 525388 ) on Friday July 18, 2008 @01:43PM (#24245051) Homepage Journal

    I always wondered why stuff always sticks to one of my sweaters..

  • by Blice ( 1208832 ) <> on Friday July 18, 2008 @01:46PM (#24245089)
    We've already reduced and even reversed casmier effects, haven't we..? []

    Or is this different somehow?
    • by Badge 17 ( 613974 ) on Friday July 18, 2008 @02:34PM (#24245713)

      The earlier work was completely theoretical - the paper in question here is an experimental result.

      Why do we care? A lot of reasons - the casimir effect is deeply rooted in quantum physics, but is observable without having to cool things to quantum temperatures. This sort of research is also potentially very important in nanotechnology - if we want our nanosurfaces to not stick, we should make them corrugated - the opposite of the macroworld!

      Many times, people have calculated these casimir forces by assuming that the quantum force between two plates by just adding up the forces between particles (pairwise additivity). This is the first (I believe) research that shows this failing experimentally - there are large-scale geometrical effects. This is exciting, as it means that there may be many ways to tune casimir forces, making them do whatever we want - theoretical predictions on piston-like geometries have forces that are attractive at one distance, and repulsive at another!

      If anyone's interested, the actual paper is at [] and better summaries (Moore's law wtf?) are at [] and []

      • if we can tune devices to make use of the casmir effect does that make us one step closer to building actual nano machines?

        or could such effect be controlled to make even smaller CPU's?

        • I'd think bigger...combine the effects of 10^XXX nano-engines painted on the bottom of a giant aluminum hollow frisbee! Earth where?
  • More Info (Score:2, Informative)

    by Thyamine ( 531612 )
    For those of us who had to look it up again: []
  • Casimir Effect? (Score:1, Interesting)

    by Anonymous Coward
    I've read the article, read the Wikipedia entry, and I still haven't a good handle on what causes the Casimir Effect. Would anyone care to elaborate a little bit for those of us in the audience whose physics background is of a more Newtonian bent? Is this a manifestation of zero-point energy? Is it energy we can extract in any useful way? Is this just a trick of electrostatic forces, or something else entirely? Thanks!
    • by Amouth ( 879122 )

      i'm not sure but it isn't a trick of electorstatic forces as it manifests between to non charged (non energetic) plates in a vacume with no pressend electro magnetic field pressend around or between the plates.

    • Re:Casimir Effect? (Score:5, Informative)

      by Blice ( 1208832 ) <> on Friday July 18, 2008 @02:00PM (#24245297)
      I don't know if it's proper /. manners to copy someone else's post, but these are the words of Roger W Moore [] ...

      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 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 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?

      • IANAP but couldn't this type of effect basically explain gravitational attraction? In philosophy of science we talked about "nelectricity" a made up force that no one can detect but people say it is there. A comparison to god and magic, (that it is pointless and more or less against Occum's Razor) but maybe some similar effect that occurs on a larger level, a stronger attraction rather than the Casimir effect's weak attraction. This "nelectricity" in this case is actually observed second hand, gravity, we j

      • Re: (Score:2, Informative)

        The Casimir force is the Van der Waals or London's force in bulk, meaning that its the same thing, but studied in relation to conducting surfaces rather than individual molecules. Casimir's original derivation, which is only a couple of pages, makes no reference to quantum vacuum fluctuations, and I think that model and metaphor tends to make the topic seem much more exotic than it really is.

        On a side note, there's no way to get free energy out of the Casimir force without using the formula 'stuff-I-don't-

      • Can you post a CID link to that? I want to follow it but I can't find it on the userpage you linked to.

      • Re: (Score:3, Funny)

        by ucblockhead ( 63650 )

        If only there were a way to create some way of making some sort of text that, when clicked, took you directly to the post.

      • Why don't the random variations also intermittently produce adjacent similar charges producing a zero vector over time?
    • There are strange quantum effects that mean that nothing can ever really be empty (I think this part is related to the uncertainty principle), but resonant cavities can be more empty than open space (because everything has a wavelength, and resonant cavities are very picky about what wavelengths they allow). So the stuff in the less empty area (outside your MEMS thingy) pushes harder than the smaller amount of stuff in the more empty area (between the parts of your MEMS thingy), and the parts all get stuck
      • So, if the Casimir effect is a resonant phenomenon, is TFA simply talking about disrupting that resonance by altering the topology of the plates with their nano-corrugations?
        • If the corrugations are a little bit smaller than the separation distance, then *maybe* (intuitively it should work, but intuition doesn't work well at these scales). If they're larger, then it's pretty much just about making the effective surface area smaller. Since the article does mention surface area, I think it's probably the latter.
  • Phew! (Score:4, Funny)

    by Ngarrang ( 1023425 ) on Friday July 18, 2008 @01:52PM (#24245185) Journal

    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.

  • If you could alter the shape of the molecules that are on the surface of the object (for example using current passing through nanowires under the surface) this could alter the force in different parts of the surface and actually cause the moving parts to move.

    For a meaningful design though, there would have to be a very good model of the strength of the force as the surface shape changes.

    If they can do that then it could well end up being an opportunity, and not a problem for nanotechnology.

  • by putigger ( 632291 ) on Friday July 18, 2008 @02:02PM (#24245327)
    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!
    • by Firehed ( 942385 )

      It also has nothing to do with being a law either. It's just a guideline as to what we may expect for the development of microprocessors.

      Well, maybe it's a corporate policy^W^W law over at Intel, but as they seem to be keeping on track, we still don't know what to expect for Gordon's Wrath.

      • sigh... (Score:2, Informative)

        by p3d0 ( 42270 )

        Law [] "A statement describing a relationship observed to be invariable between or among phenomena for all cases in which the specified conditions are met: the law of gravity"

    • all Moore's Law was ever about was the number of components in an IC. Not speed, not cost, not even size.

      Moore's "law" was actually a measure of size and cost, not necessarily the number of components.

      The initial write-up had time separated plots of cost against component density. Each was roughly parabolic, and the low point of each, which represented the lowest cost transistor density, roughly doubled over each 18-24 months.

      A my room mate actually has an Intel t-shirt with a picture of that plot on the fr

      • Roughly parabolic on a log-log scale.


        • Excellent point, I'll keep that in mind for the next time this rears it's head.

          So few people realize that increasing transistor count without decreasing their size is going to drive up the costs through raw materials while decreasing size alone will drive it up through lower yields and more costly manufacturing processes.

          The apparently exponential increase in clock speed we've seen has been more an after effect allowed by the smaller interconnect distances and lower switching voltages that are required at t

  • The author of the article was either confused or isn't explaining things well, because he writes that corrugations reduce the surface area... when the opposite is true... corrugations increase the surface area rather than reduce it. ANyone know whether that was just a typo or he's referring to something subtle that I'm too thick to understand.

    • Re: (Score:2, Insightful)

      by embsysdev ( 719482 )

      He's probably referring to the contact surface area. By making the surface corrugated, less of the surface comes in close contact to the other surface.

    • My initial guess would be that it has something to do with literal surface area vs. active surface area, the parts that are hidden (inside the grooves) don't count.
    • by Badge 17 ( 613974 ) on Friday July 18, 2008 @02:40PM (#24245795)
      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.
      • by argent ( 18001 )

        Ah, and the amount of reduction of force, then, would be effected to the relative orientation of the corrugations.

  • It runs on literally "nothing": the captured energy of vacuum energy. Much cheaper than gasoline.
  • by loose electron ( 699583 ) on Friday July 18, 2008 @02:09PM (#24245419) Homepage

    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.

    • Yes, stiction isn't about the Casimir force.
      Any two very smooth and very planar surfaces will stick together when they come so close that no more air molecules bounce around between them. In vacuum, metals will even weld together at low temperatures. That's a major problem in spaceflight.
      Stiction just means that the force to overcome the static friction (sticking together) is way higher than the normal, dynamic friction.
      I've seen disk heads ripped off by stiction :)

  • Previous Art (Score:3, Insightful)

    by PPH ( 736903 ) on Friday July 18, 2008 @03:36PM (#24246519)

    The solution to freeing a stuck mechanical device is well known.

    Hit it.

  • IINAP but...

    Since we have negative index materials that can reverse the casmir effect: []

    And we are on our way to modifying the attractive effect, there is nothing in the laws of physics prohibiting us from cycling the plates through an attractive then repulsive process, extracting force over distance (energy) in each cycle.

    We would need something like a material that can have the index changed rapidly and with minimal energy input and sandwich it

    • by Fizzl ( 209397 )

      Ah yes, I can picture it. A brand new generation of crackpots trying to extract infinite energy out of magnets, this time tiinyweenysmall :)

  • Perhaps you ought to take a look at this patent submitted recently: []
  • Extended Murphy's Laws 1. When you miniaturize your devices some quantum effect will certainly go wrong 2. Smaller the device, bigger the problem 3. Your problems will double every 18 seconds

The world is coming to an end--save your buffers!