Superconducting DNA

Mr_Dyqik writes "Alik Kasumov of the Laboratoire de Physique des Solides in France and co-workers have shown that DNA molecules act as ohmic conductors above 1K and that below this temperature they can superconduct. This could allow the creation of self assembling superconducting circuits. (A Y Kasumov et al 2001 Science 291 280). The story is on PhysicsWeb."

Comments

not simultaneously

[Goonie]

While your friendly DNA might self-assemble, and might indeed superconduct if you get it cool enough (and 1K is pretty damn cool), it's not going to do both at the same time, which if you were going to ever use this in a practical sense might be something you'd like to get it do do (to build a molecular-level write-once memory system, for instance). In addition, getting things this cold is quite hard to do, IIRC.

While this is fascinating stuff, it'd be even cooler (if you'll excuse the pun)if we could make variant DNA that superconducts at higher temperatures :-)

Anyway, one slightly offtopic question about superconductivity and the high-temperature superconductors that caused all the fuss back in the 1980's: what happened? Did we reach another temperature plateau? Was it still at liquid-nitrogen-required temperatures?

DNA does not mean genetic - Read before ranting

[vik]

Before people go off on a tangent thinking that DNA here is used as a genetic material, be advised that it is not.

The concept of using DNA for structural purposes is about as different from genetics as using mortar is to building seashells.

The DNA is only sequenced to stick to itself, not to create or emulate any gene. It is quite likely that the "genetic" content of DNA used in this manner is garbage in the genetic context. The prime requirement in fact is that the DNA used for structural purposes will not interact with anything other than the target it is to join to.

Vik :v)

Re:Below 1K - but in a small area

[vik]

Rememebr that we're talking a very, very small device here. To cool a Pentium chip of several square centimetres area to 1K would take a reasonable amount of machinery, say about 6 filing cabinet drawers worth.

But to do the same to a volume less than 1 cubic millimetre? That could be done inside a desktop case. 1 cubic mm of DNA is a hell of a lot of circuitry. At a molecular scale you can reproduce the functionality of the human brain in a few cc's - if you can keep it cold.

Vik :v)

Re:OK, someone brief me on this

[Maurice]

Superconductors were discovered in the early 1900s by Onnes (in mercury). In the 80s they discovered the so called type 2 superconductors which have much higher critical temperature, i.e. they are superconducting at higher temperatures, making it possible to use cheap liquid nitrogen for cooling instead of liquid helium. Type 2 superconductors are not metals (or have impurities) and are usually some kind of copper oxide. They have much different properties than Type 1 (which are usually pure metals).

Re:Below 1K

[Maurice]

Nope. Some things don't superconduct. Like gold or silver for example, even though they are the best ohmic conductors.

OC !!

[slashdoter]

So if Superconductors can be made out of DNA then could I make an IC out of myself? and if I could make an IC out of my own cells, then could I make a CPU out of them? and if I could make a CPU could I Overclock myself? Opps to much, time to stop smoking this shit

________

Superconductors in a nutshell.

[zCyl]

While interesting in an academic sense, such a discovery is rather trivial in a practical sense. Superconductivity itself has a number of astonishing uses that can sometimes look like magic, but they're only useful when we can get them to occur at useful temperatures. Unfortunately, cooling something to 1K will require something along the lines of laser cooling in order to achieve, and this turns out to not be very practical. Superconductors with a very low critical temperature cannot conduct much current before they exceed their critical energy level and "go normal".

Useful superconductors are more in the line of HTC's, high temperature superconductors. The simplest of these are the superconductors that work when cooled to the order of 70 degrees Kelvin (-200C) by liquid nitrogen (which is cheaper than beer). If I recall correctly, the highest published HTC was around 175K, which is only 100 degrees below freezing. I've heard rumors of higher temperature superconductors, but haven't seen any referreed publications of results yet. Keep your eyes peeled, we'll see room-temperature superconductors within the lifetimes of most slashdotters.

To be fair to lower temperature superconductors, I believe the maglev train in Japan uses a lower temperature superconductor cooled by liquid helium, which is somewhere down on the order of 10K.

Superconductors aren't too useful for their property of not conducting current, since they have a critical maximum current level anyway. They are mostly used for their diamagnetic properties (they repel magnetic flux lines). This is the basis for how an MRI works, or for how super-fast magnetic trains work.