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MIT Scientists Make a Polyethylene Heatsink
arcticstoat calls our attention to MIT research that has produced a version of polyethylene that can conduct heat away from computer chips. Polyethylene is the most widely used plastic. It's not clear how practical this research is for industrial-scale use, involving as it does an atomic-force microscope. The work is detailed in a paper published in Nature Nanotechnology this month. "The new process causes the polymer to conduct heat very efficiently in just one direction, unlike metals, which conduct equally well in all directions. ... The key to the transformation was getting all the polymer molecules to line up the same way, rather than forming a chaotic tangled mass, as they normally do. The team did that by slowly drawing a polyethylene fiber out of a solution, using the finely controllable cantilever of an atomic-force microscope, which they also used to measure the properties of the resulting fiber. This fiber was about 300 times more thermally conductive than normal polyethylene along the direction of the individual fibers, says the team’s leader..."
Plastic heatsinks, just don't get them near heat!
What next, a chocolate teapot?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Before anyone asks, the article is clearly wrong in the statement "The new process causes the polymer to conduct heat very efficiently in just one direction...", the heat moves along one dimensions, in 2 directions.
Plastic degrades over time, especially in a smoker's environment.... As the plastic expands and contracts as it heats up and cools down, respectively, won't that mess up the polymer chain and make it loose its effectiveness??
Previewing comments are for sissies!
Transferring heat in just one direction? So, we can finally boil kettle on an ice cube?
strings or strands and you could have a material that doe sin fact act as you say BUT yes in between would need insulation's
this however could be a much more efficient way to make homes with
I think they mean in one dimension, not direction. The plastic will conduct heat longitudinally a lot better than laterally, but it will conduct heat longitudinally equally well both to and fro. If they ever come up with a material that only conducts heat in one direction (a thermal "diode", if you will) then that solves our energy woes.
When our name is on the back of your car, we're behind you all the way!
Everybody thought it was plastic, but it was just new technology. Now we just have to wait for an announcement on how to mount those crazy i7's
Polyethyline is made from petroleum, a resource that's going to be increasingly scarce over the coming decades, and the process no doubt releases some significant CO2 and pollutants. It would seem by comparison there's quite an ample supply of old beer cans and airplane carcasses available for recycling.
If all polymer molecule strings are all oriented the same, is it a crystal?
This setup may show interesting optical properties as well. It's amazing research really, with processing matter at that atomic scale control. Being able to buildup matter that precisely will reveal all new dreamed uses. I really hope this will go forward as discovering industrial processes of controlling matter buildup arrangement at an atomic scale in mass-production.
Léa Gris
Since neither the summary nor the article has been kind enough to expand on "300 times more thermally conductive than normal polyethylene", I figured I'd look it up.
Thermal Conductivity of some common Materials:
Polyethylene HD: 0.42 - 0.51 W/mK
Aluminium: 250W/mK
Copper: 401 W/mK
Best case scenario: 153 W/mK or 61% as conductive as aluminium, 38% as conductive as copper. Not exactly impressive for a heat sink
This material could be another boom material for the spacecraft industry. Some of the heavier hardware on any given space payload is the thermal control system. Using a combination of heat pipes and surfaces coated in various colors of paint for heat control can add a significant amount of weight to a spacecraft. If this material can be added as a thermal layer to the MLI layers that are tacked onto the outside of a spacecraft, it may go a long way in reducing and simplifying the thermal control subsystem of the given payload. In fact, since it is a simple plastic, it should be significantly lighter than various metal contacts and conduction paths within a spacecraft that are used today.
The single dimension (not direction) transfer mechanism could also be very useful. If you can ensure that heat will move along only a single axis, you have a bit more freedom in placing sensitive components in and around your conduction paths within your spacecraft. All in all, this could be a really useful material, if it can ever be scaled up for use in industrial applications. Here's hoping.
*crosses fingers*
Motorcycles, Robots, Space Gossip and More!
Of course after being exposed to heat for a couple minutes the material transforms back into a chaotic tangled mass since the polymer molecules are only lined up the same way when at a lower temperature with less molecular volatility.
Even if 61% of aluminum axed conductivity would have some uses, a heat sink need to have good interfaces with the heat source and with air or other transfer medium. this heat sink example is really inaccurate. Considering if expectations are for moving heat from one place to another, with limited scatter dissipation, the most efficient method is by having a mechanically moving medium (liquid coolant).
Léa Gris
This fiber was about 300 times more thermally conductive than normal polyethylene
Since I couldn't find in TFA the ACTUAL measured conductivity, I turned to the internets:
Using data from the first source I found, at its highest, HDPE's thermal conductivity is 0.51 W/mK. So this material's thermal conductivity in that dimension is about 153 W/mK, or about 3/5 that of Al (250 W/mK), 3/8 that of Cu (401 W/mK), and between 1/6 and 1/15 that of diamond (900–2,320 W/mK, according to wikipedia.
So all in all, while this is very fascinating research (and I enthusiastically encourage them to continue exploring this avenue), I'm not optimistic about practical applications for computers (at least in the remote future). They would at least have to double the conductivity, while at least matching aluminum's cost - a feat that may be too difficult to overcome.
If I had a nickel for every time I had a nickel, I'd be richcursive!
Did they name it Pam?
I still cannot find the droids I am looking for...
May be not as effective, but apparently marginally saleable. the user experience so far has been terrible but that's the way it is with any new technology.
Now, to make working CPUs out of lead. Solomon's Gold to the rescue!!! Moore's law will be salvaged by modern alchemy!!!
deleting the extra space after periods so i can stay relevant, yeah.
The problem with that is that most likely, the interface for the Polyethylene heat sink would be worse than for an aluminum one; The Polyethylene molecule is vastly more complicated than the Aluminum atom, and not nearly as mobile once cast (and would be just as likely to capture little insulating pockets of air, etc.). Even if the Polyethylene molecules on the end could "mold" to the interface, there is not guarantee they wouldn't flop over and become insulating - an Aluminum sink "molded" to the interface wouldn't care, as it's isothermal.
If I had a nickel for every time I had a nickel, I'd be richcursive!
Can you make a leisure suit out of this polyethylene? I usually have problems with overheating myself whilst I'm displaying my disco dancing finesse!
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Lovely, another case of life imitates sci-fi. This development reminds me a bit of the superconductors in some of Larry Niven's books (esp. the Ringworld series). In addition to being an electrical superconductor this material was also a thermal superconductor -- and was used as a sort of sci-fi super heatsink on a few occasions. It was mostly represented by ultra-strong threads, and occasionally a woven cloth IIRC.
Generally, plastic is not electrically conductive. Which makes it good for mounting electronics. But it is also not heat conductive. Which makes it near worthless for mounting.
A non-electric conductive, but heat conductive material would be very useful. Especially if it is CHEAP. It could be used to distribute heat in buildings and not just on circuit boards.
AFM = Atomic Force Microscope, which is a tiny cantilever that probes a surface down to the atomic scale. I highly doubt this process is high throughput enough to service the electronics industry.
There must be something special about this polyethylene. The process of drawing out fibers that have molecular directionality has already been done with Spectra® Fiber. I never considered using the stuff as a heat sink. There must be something special with their treatment.
Damn it, here I was all excited at the prospect of a heat diode.
Actually, the interface between $HOT_SURFACE and $HEAT_SINK is usually coated w/ some sort of thermal grease to mitigate interface insulating effects. That little tube of goop that you use w/ your brand new ThermalTake heat sink fills micro voids w/ thermally conductive goo for both the processor and heat sink interface surfaces. Typically, a metal-to-metal interface is still mostly voids because you can only polish them so flat and smooth before you're using semiconductor grade (and cost!) processes and materials to get rid of that last bit of roughness. Or, you can press them together so firmly that they weld together, but again, this is not an economical approach and it's not good for the potentially delicate guts of the part which has the $HOT_SURFACE.
So, for what it's worth, I suspect that the molecular complexity of polyethylene vs copper isn't the real issue. And the "flopping over" of the polyethylene fibers isn't an issue because the FA explains that they're drawing the fibers w/ an AFM cantilever and thus already straight and tensioned. Now, how you make a block of the stuff and slap it onto something hot, that's the _real_ issue.
"I must not fear. Fear is the mind killer." -Bene Gesserit Litany Against Fear
is fast and bulbous, got me?
They work great with the processors from Newegg!
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-- It is the mark of an educated mind to be able to entertain a thought without accepting it. -- Aristotle
What they basically built is a heat diode of sorts.
You're probably right, but it's not what the article says ("one direction"). One can always hope that Maxwell's Demon will eventually be sighted...
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
I'm not too clear on the manufacturing details here. But the material itself sounds a lot like the original Polaroid film (not the photographic kind, the polarizing kind), which is a type of plastic polymer, impregnated with iodine, which has been stretched in one dimension to align the polymer molecules along that dimension. The iodine atoms are able to conduct electrons between themselves, effectively forming "wires" which absorb radiation polarized along the direction of the molecules. I wonder if a block (as opposed to a sheet) of such a material would also conduct heat along one dimension. Things which conduct current also conduct heat well.
I suppose the devil is in the details, and the real accomplishment here is not the alignment of the molecules, but the ability to do so throughout a block of material instead of just a thin sheet. But what if you just made a bunch of sheets and stacked them up to make a block?
No, no, no. Demons are chaotic evil, Devils are lawful evil, totally different things. DnD has taught me that much, at least. There's no indication that any of the demons in the band mentioned in that song were of the variety spoken of by Maxwell!
On the other hand, Maxwell's Demon brings order (law) to chaos. Maybe Maxwell misspoke and was talking about a devil?
*Sits down to think on the subject*
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
Okay, so drastically improving the thermal conductivity of a plastic is pretty neat, but can they— using similar molecular alignment methods —take materials that are already good heat conductors and make them EVEN BETTER heat conductors? The idea of a metal that only conducts heat in one direction and does it VERY WELL has interesting prospects.
If they can get a means of mass production to the point where it achieves the desired results more often than not, they could test the heatsinks after production and bin them by performance. As long as it performs better than the unmodified base material, it'd probably be worth it to the performance PC market. (And small high performance heatsinks are always desirable in a lot of industries.)
Friend: "The NIC is misconfigured..." Me: "No prob, I'll just telnet in and fix it." *Silence*
They have some flies. Quite a lot in fact. But they can accommodate plenty more.
This is great news! Now we just need them to apply it to the various Thermo-Electric converters mentioned on slashdot earlier to create self-charging laptops!