Design by DNA

By Spencer Reiss June 2005 

DNA molecules provide the architecture for all living things. New York University chemist Ned Seeman thinks they could also be a perfect assembly platform for the smallest computing devices ever built.

How do you build things out of DNA?

We don't. DNA is just a way of organizing materials on a molecular level. It's scaffolding. For instance, carbon nanotubes--how are you going to organize them into a circuit? DNA gives you a way to arrange them into something useful. Because it has a very precise structure, and because you can control how other molecules associate with it, it's just punching a sequence into a machine. And because DNA self-assembles, if there are things attached to it--micro metallic particles or carbon nanotubes--those will self-assemble along with it.

DNA's a linear molecule. Why doesn't everything you make wind up being linear?

We use a synthetic form, which we program to give us branch points. Think of the double helix as two lanes of a highway; branched DNA corresponds to intersections. You can make molecules of pretty much any shape or size you want.

What kinds of things have you made?

Lots of crystals. The earliest complex device was something that changed its shape in a controlled fashion when you added a chemical. Last summer, we did a little walker that moved across a DNA "sidewalk." Each foot was tied down by a strand of DNA. We would rip off that strand, and then the foot was free to wander around, and then we'd put in another strand to tie it down and make the next step.

How does computing come in?

As things in the computer world keep getting smaller, they're reaching the point where top-down approaches--trying to make big things smaller--are hitting the wall. What we're doing is building from the bottom up--taking little things and make them bigger. And DNA lets you do true 3-D integration. There are issues of cooling and power loss that have to be addressed, but the point is that what we're doing is inherently three dimensional, which at the nano level is pretty amazing.

So is nanomanufacturing imminent?

We are probably not going to be using this approach to knit customized sweaters. DNA is expensive stuff; for now, at least, you wouldn't want to use it for large-scale anything. But
3-D configurations of atoms, or molecules, or nanoparticles--that has to have value, in terms of making things no one has been able to make before.

What about nanotech's skeptics?

Everything we're talking about is doable. Is it doable on a scale that's going to be worthwhile? No one knows. In 25 years we've taken something that was in my imagination to the point where we can take out patents and where there are now whole conferences devoted to the topic.

    TechnologyReview網(wǎng)5月11日消息,，眾所周知,，DNA決定了所有生物體的結(jié)構(gòu)。紐約大學(xué)化學(xué)家Ned Seeman借此認(rèn)為人們同樣可以利用DNA技術(shù)來(lái)組裝微型計(jì)算機(jī)元件,。

    DNA可以從分子級(jí)控制生物體的組織結(jié)構(gòu)，例如,，如何把碳納米管組成一個(gè)完整的電路,？DNA技術(shù)或許就可以提供一種有效解決方案,，因?yàn)樗哂袠O其精細(xì)的組織結(jié)構(gòu)。人們可以利用DNA技術(shù)控制分子之間的連接,，使其成為可以運(yùn)作的電子元件,。

    科學(xué)家們最早通過(guò)向晶體中添加不同物質(zhì)來(lái)改變晶體的分子結(jié)構(gòu)。DNA是線形結(jié)構(gòu),，但它產(chǎn)生的生物體卻不是線形,。因此，DNA技術(shù)或許可以制造出三維電子元件,。

    隨著計(jì)算機(jī)電子元件的體積日漸縮小,，所需的工藝也日趨復(fù)雜，人們已經(jīng)很難再利用傳統(tǒng)工藝制造出更小的元件?，F(xiàn)在科學(xué)家想辦法從相反的方向考慮,，他們將從分子級(jí)出發(fā)，讓分子有序排列從而制造出可行的微型元件,。DNA技術(shù)有可能完成這項(xiàng)工作,。電子元件的散熱量和功率一直是人們關(guān)注的焦點(diǎn)。納米級(jí)的電子元件在此方面會(huì)表現(xiàn)出卓越的性能,。

    人們不可能利用DNA技術(shù)去制造一件毛衣,。因?yàn)檫@是昂貴的制造工藝。所以,，人們只可能利用DNA技術(shù)制造微型元件,。并且，人們必須利用DNA技術(shù)制造出普通工藝無(wú)法做到的元件才能取得應(yīng)有的價(jià)值,。

    沒(méi)有做不到,，只有想不到。問(wèn)題是科學(xué)家們想到的東西是否能夠給人類(lèi)帶來(lái)應(yīng)有的價(jià)值,。目前人們對(duì)這個(gè)設(shè)想是否會(huì)產(chǎn)生利潤(rùn)還不能肯定,。