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18th Century Pigment to Revolutionize Chip Design?
Scarlet X writes "Researchers at the University of Washington have discovered a possible nonvolatile magnetic semiconductor and are investigating its use for 'spintronics,' an emerging technology that is concerned with manipulating and controlling the charge, flow and magnetism of electrons. The possibilities for the material 'cobalt green,' a paint developed by American Revolution era artists, as a spintronics material is exciting. Should the magnetic properties of the paint at room-temperature prove able to reliably control the wild spinning of excited electrons in a processor, not only could the size of processors reduce substantially, but the constant limiting factor, how to keep things cool, could disappear."
Hummm. AsI am not a EE or physics, I am curious. In your statement, you imply that the simple use of electricty (i.e. work) generates heat. My understanding is that heat is not part of the work, but due to the inefficiencies of the process. The more efficient, the less heat. For example, a regular light bulb (fairly inefficient as it generates lots of heat) vs. the LED (very efficient and with little heat). Or is my physics off base?
I prefer the "u" in honour as it seems to be missing these days.
As a watercolour pigment, cobalt green is increasingly hard to find. Winsor&Newton no longer stock, nor DalerRowney. The only remaining major supplier seems to be Schminke. It's a really useful colour for making lively blacks, but the point of mentioning here is that these paintmakers all cite poison/health/product liability issues as reasons for its withdrawal. Best not kiss your circuit board any more than you should lick your brush tips.
You are correct; simply because energy is expended does not mean it's lost in the form of heat. The idea of this paint is that it's magnetic properties control the electrons and, in theory, stops them pumping into things. When they are stopped from bumping into things they won't lose energy - in much the same way that a super-conductor works.
When energy is used to do work (i.e. lighting a room), then yes, the heat generated is due to an inefficient process, but that doesn't mean that it is possible to have a 100% efficient process. Actually, the second (?) law of thermodynamics states that a 100% efficient process is only possible at absolute zero. On the other hand, a processor produces no work, i.e. there are no moving parts, it doesn't produce light, it doesn't make sound or an electric current. The only thing it does is move electrons around, i.e. changes its entropy. You need energy to do that, but it's not work: the total (useful) energy emitted by the processor is zero, and all energy used goes off as heat. There is a theoretical limit to the amount of energy needed to flip a bit, spintronic might approach that limit better than electronics, but wil not break it, and this energy will still be emitted as heat.
You would need a pretty small brush to make them work fast enough to be really useful.
Someone like Chinese micro-painter Jin Yin Hua who has painted an image of a giant panda on a single human hair could really do it justice.
However for simpler curcuits it could be good to do.
I personally would prefer to put this ink into an inkjet printer and get better results.
liqbase
This research has been going on for a long time - you may have heard of it here and it's likely going to take a while before we see it since it still needs to be perfected and then economical and make its way into industry. As far as I can tell by reading the UWNews article, all they did was discover that an old pigment can work. Not that it isn't cool, but it's not really likely to advance science significantly, especially because a previous article in PRL which was published in 2004 mentions this effect.
Shameless copy from wikipedia:
While the timeframe is correct, the sentence in the posting (to me) suggests it's an american invention...
Sorry for the slightly off-topic, non-american-centric post. Now please continue enjoying your duplicates^H^H^H^H^Hexiting new stories and comments ;).
Intosi
Due to the design of semiconductor transistors, they have on (conducting - high amps, low volts) and off (non conducting - low amps, high volts) states. These discrete states have very low losses (power = volts x amps).
Unfortunately, during the transistion there are nanoseconds where it is in the partially conducting state. Both the current and voltage are at intermediate values, and the power dissipation rises. The more often they switch, the more often these losses occur, which is why CPU heat is dependant on the operating frequency.
Spintronics may use a fundamentally differnt signalling mechanism which doesnt involve these transition losses.
A processor does do significant work. For example, the electrons in the channels of the transistors move against some finite resistance, phonons are released as electrons fall from the conduction band into the valence band, etc. It only doesn't produce light because there is a momentum change (hence the phonon) when the electrons do so. In direct bandgap semiconductors, light is released, hence LEDs and semiconductor lasers. The reason there is heat in any processor is the fact that unless there is some resistance somewhere, the clock rate could be infinite since it would imply that any capacitance could be charged up in zero time.