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Power Science

Generating Nano Oscillatory Motion 70

KentuckyFC sends us to, where he summarizes (in prose that is somewhat more twee than we usually encounter in writing about physics) the conversion of a constant force into oscillatory motion on the nano scale. Here is the article preprint. A research group at the University of Wisconsin-Madison has made mushroom-shaped nano-pillars that oscillate in a constant DC field, like metronomes.
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Generating Nano Oscillatory Motion

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  • Twee (Score:4, Informative)

    by camperdave ( 969942 ) on Friday August 24, 2007 @05:55PM (#20348635) Journal
    Twee: Nausiatingly cute. []
    • Re: (Score:3, Informative)

      by MontyApollo ( 849862 )
      The title is "Invasion of the jivin' nano-shrooms" just to give you a taste of the twee.
    • by Otter ( 3800 )
      All the entries seem to be written that way. It's irritating and not even funny the first time, let alone repeatedly, but the practice of giving cited researchers a Chris Berman-esque nickname is a nice innovation in the world of science journalism. Even if the nicknames are hardly (and I never thought I'd write these words) up to Chris Berman's level of cleverness.
    • Well, I just learned something. I had thought that "twee" meant gay, and I was wondering why kdawson was being so hypocritical as to call someone else gay.
    • by billsf ( 34378 )
      Twee = two. Didn't know it had an English meaning.
    • Twee: Nausiatingly cute.

      From TFA:

      Convertin' a constant force into an oscillatin' one is a useful trick. Ya'll seen em:

      Blech. X-(
      :. Q.E.D.
    • Re: (Score:3, Funny)

      by Hatta ( 162192 )
      Q: How do you titillate an ocelot?

      A: Ocillate it's tit a lot.
    • by Achoi77 ( 669484 )

      *grumble* after reading that I didn't think it was that twee.. me it felt a little more.. foghorn-leghorn

  • by Prysorra ( 1040518 ) on Friday August 24, 2007 @06:04PM (#20348717)
    So they tilt to the beat, do they?

    Well.....they still aint got nothing on the singning mushrooms from Tength Kingdom!

    Ah.....suck an elf.
  • Smaller Scale Still (Score:3, Informative)

    by Nom du Keyboard ( 633989 ) on Friday August 24, 2007 @06:05PM (#20348719)
    Excuse me, but, doesn't this happen on the atomic level? Apply heat, and atoms vibrate.
    • Yeah, but atoms aren't as cute as nano-mushrooms!
    • by jimbug ( 1119529 )
      yes, but do they jive?
    • by jcorno ( 889560 ) on Friday August 24, 2007 @06:15PM (#20348805)

      Excuse me, but, doesn't this happen on the atomic level? Apply heat, and atoms vibrate.

      Yeah. At random frequencies, and in random directions. What good is that?
      • by camperdave ( 969942 ) on Friday August 24, 2007 @06:32PM (#20348979) Journal
        Well, by simply hooking the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea) one could make all the molecules in a hostess' undergarments leap one foot simultaneously to the left in accordance with the theory of indeterminacy. Some people might use it to break the ice at parties.
        • I've always loved that description, except I've never thought that one foot was nearly enough. Wouldn't the waitress just end up with one bare leg, and the other in the wrong leg-hole? And even more importantly, whose left?!?
          • And even more importantly, whose left?!?br>
            I wouldn't know. I don't get invited to those sorts of parties.
    • They need regular motion, like a pendulum, and it's more than one atom working together. Applying heat makes individual atoms move randomly and generally not in the same direction as others.
  • (Emphasis mine)

    The force disappears and the mushroom's stiffness sends it swinging back to the source again like metronome, and the process starts again.

    Voila! A nanomechanical oscillator that converts a a constant force into an oscillation.
    Huh. A force which is NOT constant is described as a constant force. Nice. This is just the charged-ping-pong-ball-near-a-Van-de-Graaf generator experiment, only writ on a small scale.
    • You are mis-reading the article...

      Give the mushroom a push and it leans towards the source electrode where electrons tunnel across into the mushroom head. The DC field exerts a force on this extra charge on the 'shroom, pushing it towards the drain electrode where the electrons jump ship. The force disappears and the mushroom's stiffness sends it swinging back to the source again like metronome, and the process starts again.

      The stiffness/weight/pressure/whatever is the constant force. The (constant) DC field works in conjunction with the charge on the mushroom head pulling it to the drain electrode - which drains the charge - and then the (constant) stiffness/weight/etc pulls it back to the source electrode where the mushroom head gets "re-charged" - thus starting the whole process all over again...

      • I understand that the DC force from the electrodes is essentially constant. However, the total force on the "mushroom" is NOT constant (as you state in your post). I read the summary as giving a whole lot of emphasis on this "constant force" thing, which is probably my mistake.

        It's really no different a concept than seeing a bouncing ball as subject to a constant (gravitational) force, except when it's not, as when the concrete smacks it back upward.

        Perhaps this i
        • Re: (Score:3, Informative)

          It's really no different a concept than seeing a bouncing ball as subject to a constant (gravitational) force, except when it's not, as when the concrete smacks it back upward.

          If you have an oscillating body of a given mass, then obviously the net force on the body isn't constant, given F=ma. There's no question about that (though it would certainly be newsworthy if someone discovered that F=ma doesn't hold). The question here is whether the input force is constant. The story is that they've replicated on a

          • The story is that they've replicated on a nano-scale turning a constant force input into an oscillating net force at the point of interest, something which has apparently not been done before.

            Good point. However, I'd bet that it's NOT a constant force input, as they're using a lock-in amp to monitor things. That implies an oscillating voltage on a measureable scale. After all, as the mushroom head traverses the space, the Coulombic repulsion on the electrons waiting at the pick-up site decreases; once the electronic cargo is dropped off and starts wandering down the egress wire, this force disappears (assuming a grounded oscillator).
            I don't know if this has been done on

      • Analogous to a nanoscale version of (Ben)Franklins Bells?
  • by gardyloo ( 512791 ) on Friday August 24, 2007 @06:17PM (#20348831)
    ... Jumping electrons = badgers;
                nano-pillar = mushroom;
                I'm still working on the "Snaaaake! Snaaaake!" bits.
    • by jd ( 1658 )
      I've a different song in mind - Bad Karma in the UK. Getting the lyrics to work is much easier when they never made any sense anyway.
  • The paper has very few details. The thoughts I get are:
    1) Hints of 'room temperature' superconductors.
    2) A new type of amplifier -- only maybe.
    3) A joke paper. That seems to be what most think.
    The charged ping-pong balls on the van der Graf generator is a nice explanation. 16VDC on the nano-scale is HIGH VOLTAGE.
  • by Roger W Moore ( 538166 ) on Friday August 24, 2007 @07:14PM (#20349233) Journal
    Firstly electromagnetism is understood down to scales many orders of magnitudes lower than the nanoscale. QED is the second most accurate scientific theory ever (special relativity is the winner) and works at distances considerably less than nuclear diameters (one million times smaller than nano-scale). Secondly a pendulum does not convert a constant force into an oscillation because it has to have an initial excitation in the form of an applied force. This force must be applied and then removed so it is non-constant. Even if we ignore that the pendulum requires a string tension to work and that is an EM force so it is wrong to think of it as pure gravity. Conclusion: this guys physics is as heavily accented as his american.
  • that's the term my gf used when she mentioned having sex with her ex-boyfriend.

  • I hate when I'm a geek and still don't understand the news on Slashdot. :-(

    I'm Swedish so I didn't even understand the word "twee". Now I at least added it as a keyword for the story, and I think I'm done here.
  • But, I for one welcome our mushroom-shaped nano-pillar overlords!
    • by searob ( 1147641 )
      It hasn't been said yet before you, and it shouldn't. Ah! This getting so old and over-used.
  • Your average slashdotter produces millions of nano-oscillators daily, and usually releases them while imagining covering a naked and petrified Natalie Portman in hot grits. All it takes is one hand, a few minutes, and a locked door.

  • Its interesting how everyone seems a lot more concerned with the language used to report this bit of science rather than the discovery itself. The comments on the original blog entry are quite interesting. Several people complain about the "southern slang" or "aww-shucks" style of writing. I looked at it and thought "hip-hop lyric" myself.

    We're all getting at something, aren't we? I also wonder if people complained this much when science journals began switching from Latin and German to English.

    • This isn't like switching from one recognized language to another so more of your audience can understand. This is intentionally using bad grammar that's likely to make it harder for your audience to understand, in the name of spicing up boring science/getting attention daddy never gave you/looking cool to people who don't get it anyway/some other stupid reason.
  • What is the sounds of one hand clapping?
    What is the sound of a DC field causing oscillations?

    It is one and the same thing.

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