Generating Nano Oscillatory Motion

KentuckyFC sends us to arxivblog.com, 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.

Twee

[camperdave]

Twee: Nausiatingly cute. [worldwidewords.org]

Re:Twee

[MontyApollo]

The title is "Invasion of the jivin' nano-shrooms" just to give you a taste of the twee.

Smaller Scale Still

[Nom du Keyboard]

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

Re:(YES it is) - Re:NOT a constant force.

[Control Group]

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 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.