Comments on: A billion smiley faces in a drop of water

A billion smiley faces in a drop of water

todbot — Thu, 16 Mar 2006 12:52:09 -0800

A billion smiley faces in a drop of water. In this month's Nature, Caltech researcher Paul Rothemund has described a method of creating nano-scale structures using DNA in a process simple enough for high-school chemistry class. This is the real nanotech.

By: rxrfrx

rxrfrx — Thu, 16 Mar 2006 13:03:56 -0800

Brilliant and beautiful. Totally one of those elegant "I can't believe I didn't think of this" things. It will be interesting to see what applications come out of this.

By: goethean

goethean — Thu, 16 Mar 2006 13:29:00 -0800

Is it me or does that smiley face look a little menacing?

By: swordfishtrombones

swordfishtrombones — Thu, 16 Mar 2006 13:35:22 -0800

That is indeed awesome. Is it me or does that smiley face look a little menacing? What do you expect? It's made from a virus!

By: carsonb

carsonb — Thu, 16 Mar 2006 13:39:20 -0800

if there's any chance at all this could be what the grey goo that kills me in a few years looks like, that would be great. thanks. this is neat!

By: pantsrobot

pantsrobot — Thu, 16 Mar 2006 13:45:52 -0800

And does the high school chemistry class have an "atomic force microscope"? Haha, just trolling, this is very neat

By: Aknaton

Aknaton — Thu, 16 Mar 2006 13:51:58 -0800

Ha! Roto (Paul Rothemund) hits the big time! He mentioned to me some reason that three holes is a natural maximum for this construction. (Strangely, I can't find this mentioned in the Nature article, though it does have cool pictures of 5-pointed stars, in addition to the smiley faces.) "So you have to make a smiley face, obviously."

By: todbot

todbot — Thu, 16 Mar 2006 14:06:53 -0800

Yeah, disclaimer: I went to school with Roto too. Yay Roto!

By: lalochezia

lalochezia — Thu, 16 Mar 2006 16:18:01 -0800

I know Paul, and work in a lab that trained his mentor in the practical side of things. I've seen a lot of "DNA Nano" (and produced some myself) but I'll say to you what I said to paul when I saw the pre-print: FUCKING WOW. The molecular pegboard idea is huge: implement any arbritary 2d scaffold for virtually any other nanosized component using commercially available synthetic DNA without purifications in an automatable process. This is so elegant I still become speechless a year after seeing the original AFMs. In short . That's an nano-sized . for you

By: hattifattener

hattifattener — Fri, 17 Mar 2006 10:33:09 -0800

Pants, if they don't, maybe they could build their own. For about $200.

By: nickp

nickp — Fri, 17 Mar 2006 20:35:08 -0800

Aknaton: Three holes is not a maximum for this technique. It was more a matter of "If I can do three, then I can do pretty much any number ... what's the coolest pattern I can make with three?" At no point in the paper does he refer to it as a smiley -- just "the disk with three holes" ... Disclaimer: I was peripherally involved in this, and worked on some of the cover art. The smiley was supposed to look a bit halloween-ey.

By: Aknaton

Aknaton — Sat, 18 Mar 2006 15:10:52 -0800

Some updates from Paul:

"Three holes was no limit but I treated it as a psychological milestone. I started off thinking, I'll make a square washer with 1 hole to show it can be done. Then I thought, "Someone may wonder if there is a limit, I should add some more holes, 3 ought to make them feel like there is no limit and I have the mental energy to cook up a folding path for three holes (without going mad)." "[Something] that frustrated me was that NPR said that my program could "analyze a shape and generate a design". This could be done easily but my program doesn't do it. One has to describe the folding path by hand and then the program figures out the DNA sequences to create it. I hope this doesn't create any false expectations of my crappy code and I hope that someone rewrites it nicely to include this feature."

By: rxrfrx

rxrfrx — Sun, 19 Mar 2006 06:16:11 -0800

Why are there so many MeFites involved in this project?

By: rxrfrx

rxrfrx — Sun, 19 Mar 2006 06:16:54 -0800

Also, does anyone think this could be used to (more) easily make a catalytic DNA? (I haven't RTFJA yet)

By: nickp

nickp — Sun, 19 Mar 2006 11:12:07 -0800

Why are there so many MeFites involved in this project? Many of the folks in DNA nanotech -- at Caltech and elsewhere -- started off as computer scientists. Thus they (and their friends) are probably over-represented on the net. As for catalytic DNA -- People have already evolved a number of catalytic DNA's (although RNA seems to be better for this sort of thing). Having a scaffolding (which is what this technique provides) might enable some interesting experiments involving precise positioning of (any) catalyst with a substrate.