Sandia Builds Micromechanical 'Device Driver'

DanielRavenNest writes: "Sandia Labs has built a tiny bicycle chain type drive out of silicon. This allows one micromechanical motor to drive multiple devices scattered about a chip."

Comments

[mirror] Google's Mirror

[BrianGa]

Here's Google's mirror, since it looks like this site was /.'ed.

Article on MEMS research

[Stone Rhino]

here (free regblah.)
AND for cut and pasters: http://www.nytimes.com/2002/01/10/technology/circu its/10NEXT.html

Re:How are these made?

[Anonymous Coward]

It is actualy quite easy, the gears that you see in the pictures are made out of poly silicon. So what you do it grow a thick (several micron) sacrificial oxide, pattern the oxide using standard lithography. Etch out the pattern of the gears, creating essentaly a mold of the gear. Then you backfill the area with poly silicon. You then preform a oxide etch with a HF acid solution and remove the oxide, leaving just the poly silicon gears. You grow the oxide, etch, fill, and repeat. This process is done several times to created diffrent levels. So as an example, the bottom of the chain would be layer 1. The Drive gear and the vertical post that connect the top and bottom of the chain are layer 2. Then the top of the chain is layer 3.

Re:How are these made?

[Arjuna Theban]

They can be actuated with a bunch of different methods. The easiest is a comb drive. I'll let you read up on it. As for how they are made: Most gear-like structures are built with "surface micromachining" ie: building up on silicon with SiO2, polysilicon, metal, various epoxies like SU-8 etc. There is, however, another way to build many structures too, it is bulk micromachining. In bulk micromachining, the device is built on a single crystal silicon, that is, by etching into the silicon and having the body of your machine be the silicon you started with (and of course the other various materials I said before). For all of you who wonder how bulk micromachining works, I suggest you check out Berkeley's "Single Crystal Reactive Etching and Metallization" (SCREAM) process.

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Cool!

[Pinball Wizard]

Although this kind of stuff is not exactly new, it's still damn interesting.

My mom is an engineer at SNL, and I try to go once a year when they have their open house for families. The place is packed with stuff just as cool as this - supercomputers, particle colliders, nanotech, rockets and sattelites, I could go on and on. Really an amazing place - reading about it doesn't compare to seeing it in person. I highly recommend visiting if you get the chance.

Re:Possible Use...

[wsherman]

This particular chain is probably too big to see much brownian motion. Something like the ion channels that control the movement of ions across cell membranes might be more the right size.

If one could design an ion channel that allowed ions to diffuse in one and only one direction one would have a battery that never needed charging. Of course, if that were possible evolution would probably have done it already. On the other hand, as I understand it, Boltzmann's H-Theorem only applies to dilute gasses so it remains to be proved that such a thing is impossible.

Maybe the reason that humans are smarter than animals is that the neural ion channels in human brains have evolved to overcome the Second Law of Thermodynamics. It would be interesting to know if anyone has ever looked at whether ion channels obey the Second Law.

The second law stops you hot

[MarkusQ]

Consider hooking this thing up to a Brownian Ratchet, such as discribed by Feynman in his lectures

The Brownian Ratchet you describe won't work, because of the second law of thermodynamics. The second law is potent enough that even evoking Feynman's name won't make it go away. Besides, what Feynman described was why this won't work.

See Chapter 46 of the Lectures if you want the details, but in short, it would quickly get hot enough that its own shaking (heat=random motion remember?) would drown out the Brownian motion.

-- MarkusQ