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MIT Scientists Make a Polyethylene Heatsink

kdawson posted more than 4 years ago | from the just-one-word-young-man dept.

Science 153

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..."

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153 comments

Thar she blows! (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#31452560)

Thar be niggers in them there waters!

Re:Thar she blows! (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#31452726)

Thar be niggers in them there waters!

Big fat niggers too. They might be poor, they might be criminals, but somehow they still manage to get Plus-sized. Must be those greasy buckets of KFC.

What's the difference between nigger pussy and a bowling ball? If you had to, if you REALLY HAD TO, you could eat the bowling ball.

Why do fat nigger bitches like to keep their legs open during picnics? It keeps the flies away.

Re:Thar she blows! (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#31452832)

But don't niggress vagoos have flies around them already?

Plastic heatsinks? (4, Funny)

cbope (130292) | more than 4 years ago | (#31452582)

Plastic heatsinks, just don't get them near heat!

Re:Plastic heatsinks? (4, Funny)

idontgno (624372) | more than 4 years ago | (#31452648)

All of a sudden Newegg's "counterfeit Intel i7" with its plastic "cooler" [geek.com] makes sense!

Re:Plastic heatsinks? (2, Funny)

noidentity (188756) | more than 4 years ago | (#31454524)

Sounds like NewEgg accidentally shipped some top-secret prototype chips which us plebs didn't even know how to use. I suppose that was why they made them appear to be plastic toys, so that we'd never figure out how to interface to them. In reality, they have advanced plastic heat sinks (electrical insulators), and even more advanced plastic processors. There's a knock at the door, one mome

Awesome (2, Funny)

Hognoxious (631665) | more than 4 years ago | (#31452594)

What next, a chocolate teapot?

Is it electrically conductive? (2, Insightful)

Simonetta (207550) | more than 4 years ago | (#31453672)

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.

Article is wrong. (5, Interesting)

Anonymous Coward | more than 4 years ago | (#31452618)

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.

Re:Article is wrong. (4, Informative)

krnpimpsta (906084) | more than 4 years ago | (#31452660)

Yes, I was really intrigued and confused, after reading the line:

"The new process causes the polymer to conduct heat very efficiently in just one direction,"

I was thinking, wow, is this even possible? If this is true, I think they've just created a material that could behave like a passive air-conditioner, heater, refridgerator, etc., while using NO power, ever. That alone must be breaking some serious laws of thermodynamics..

"One dimension" or "one axis," would have been more appropriate than "one direction."

so you make it in lines (0)

Anonymous Coward | more than 4 years ago | (#31452790)

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

Re:Article is wrong. (1)

Aphoxema (1088507) | more than 4 years ago | (#31452882)

Thermodynamics are overrated and inconvenient for science fiction. Fuck it, fuck relativity and causation! It's all too boring!

Re:Article is wrong. (1)

twidarkling (1537077) | more than 4 years ago | (#31453194)

Damn straight! And to prove my solidarity...

*whips a cloth off a table* I present my PERPETUAL MOTION MACHINE! Now with plastic cooling for more efficient operation.

Re:Article is wrong. (0)

nobodylocalhost (1343981) | more than 4 years ago | (#31452946)

huh? surely you kid. How does one way heat removal break laws of thermodynamics? We already have such technology, and it is called a water tank. You connect a heat source to the bottom of a water tank, as it heats water on the bottom, the density of water in vicinity decreases and flow upward in one direction.

Re:Article is wrong. (3, Informative)

srussia (884021) | more than 4 years ago | (#31453006)

krnpimsta said:

Yes, I was really intrigued and confused, after reading the line: "The new process causes the polymer to conduct heat very efficiently in just one direction,"

You said:

You connect a heat source to the bottom of a water tank, as it heats water on the bottom, the density of water in vicinity decreases and flow upward in one direction.

He was talking about conduction. You're talking about convection.

Re:Article is wrong. (3, Interesting)

Rob Riggs (6418) | more than 4 years ago | (#31453080)

Read up on Maxwell's Demon [wikipedia.org] . I think the key piece you are missing is that this would be passive heat removal.

Re:Article is wrong. (1)

jeffmeden (135043) | more than 4 years ago | (#31453216)

No; you too are wrong. The key missing point is a fiddle. And, possibly, an improbable wager. Then we will know if the material will perform as expected, or if it will run afoul of 'the demon'.

Re:Article is wrong. (0)

Anonymous Coward | more than 4 years ago | (#31453920)

Comments about Georgia and soul stealing are clearly off topic.

Re:Article is wrong. (2, Interesting)

Chris Burke (6130) | more than 4 years ago | (#31453666)

You connect a heat source to the bottom of a water tank, as it heats water on the bottom, the density of water in vicinity decreases and flow upward in one direction.

Yes because that's also the direction of the heat gradient vector. Put a refrigerator at the bottom, and you'll soon find that the transfer of heat is now reversed.

If heat could only transfer from the bottom of the tank to the top, and if the top of the tank was much hotter than the bottom but heat was not transfered to the bottom, then that would be transferring heat in one direction, in the sense meant by the GP, and would violate thermodynamics.

Re:Article is wrong. (2, Interesting)

Mashdar (876825) | more than 4 years ago | (#31454310)

I said this elsewhere but I'll say it here too:
Thermal bias != Maxwell's Demon.

The second law does not require that heat flow from hot to cold, only that there is a net increase in heat. Obviously this requires an external energy source, though. And the water example is not a thermal bias, no, but it is a neat case. The water actually DOES transmit heat through a vertical column much faster in an upward direction via convection, than cooling (which is only aided by convection under 4C, which is an inflection point in the T/D curve for water). In steady state the water will approach thermal equilibrium, but the rate at which equilibrium is reached is vastly different depending on the direction of the thermal gradient.

Re:Article is wrong. (1, Funny)

Anonymous Coward | more than 4 years ago | (#31453002)

"That alone must be breaking some serious laws of thermodynamics.. "

Only the funny laws of thermodynamics can be broken.

Re:Article is wrong. (2, Funny)

barocco (1168573) | more than 4 years ago | (#31453088)

Prime example of why scientists can never be successful in business: as soon as s/he finds a potentially tremendously profitable idea, s/he questions whether certain laws would be broken.

Re:Article is wrong. (1)

Lumpy (12016) | more than 4 years ago | (#31453488)

I do that every day.

I invented a great new media center PC! It breaks about 78 US laws and 107 international laws.

In fact watching a movie on it will get you the Death penalty in 6 states!

Re:Article is wrong. (0)

Anonymous Coward | more than 4 years ago | (#31454040)

In other news, Steorn invents the Miniature Ferris-Wheel. Venture Capitalists Pile On.

Re:Article is wrong. (1)

quax (19371) | more than 4 years ago | (#31452950)

Very happy to see that this was immediately corrected by this AC comment. Thermodynamics does not allow for heat conductivity in just one direction. If such a material was possible it'll be simple to arrange it in such a manner that entropy spontaneously decreases e.g. having heat conducted one way towards a water reservoir. This accumulated thermal energy could than for instance be used to power a sterling engine making this a second class Perpetuum mobile [wikipedia.org] .

Re:Article is wrong. (2, Informative)

jank1887 (815982) | more than 4 years ago | (#31453260)

Just for argument's sake, the jury is still out on 'thermal rectification'. The key is just that you can't ignore certain parts of entropy generation that will exist in such a device. Here's an abstract link from a young professor at UC-Riverside, currently getting a DARPA Young Investigator Award.

Solid-State Thermal Rectification With Existing Bulk Materials
http://dx.doi.org/10.1115/1.3089552 [doi.org]

As long as the system results in a net entropy increase, some versions of the theory say its possible.

Re:Article is wrong. (0)

Anonymous Coward | more than 4 years ago | (#31454802)

abstract link from a young professor at UC-Riverside

Ooh... If only the author of that abstract were a "distinguished but elderly" scientist, we could all take him at his word for what is possible.

Re:Article is wrong. (1)

ArsonSmith (13997) | more than 4 years ago | (#31453410)

How would this be any different than the little spiny things in the light bulb with one dark side and one shinny/white side using heat difference to spin. You're not generating perpetual motion, you'd be using energy from the environment, it'd just resemble perpetual motion in that you'd wouldn't directly see the energy you'd just see a cold spot and a hot spot.

That said, i don't believe it to be possible, but not on any laws i know.

Re:Article is wrong. (2, Informative)

quax (19371) | more than 4 years ago | (#31453610)

The little spiny thingy is a perfectly "normal" heat engine in that it exploits a thermal heat difference that is created by an influx of energy from an external source i.e. the photons that heat up the dark side.

The difference with a ideal uni-directional heat conductor is that it allows to create the heat imbalance out of thin air i.e. without putting in additional energy the entropy of the system is lowered. The wikipedia article that I linked to explains this in a bit more detail:

A perpetual motion machine of the second kind is a machine which spontaneously converts thermal energy into mechanical work. When the thermal energy is equivalent to the work done, this does not violate the law of conservation of energy. However it does violate the more subtle second law of thermodynamics (see also entropy). Such a machine is different from real heat engines (such as car engines), which always involve a transfer of heat from a hotter reservoir to a colder one, the latter being warmed up in the process. The signature of a perpetual motion machine of the second kind is that there is only one heat reservoir involved, which is being spontaneously cooled without involving a transfer of heat to a cooler reservoir. This conversion of heat into useful work, without any side effect, is impossible, as stated by the second law of thermodynamics. In contrast, a hot reservoir inside an internal combustion engine is created by a spark igniting fumes which contain stores of chemical potential energy. The temperature of the fumes increases above that of the surroundings. This is not a perpetual motion machine since the increase in temperature is a result of the release of a finite available amount of chemical energy, which is always much less than the total heat energy and mass-energy contained within the system. As explained by statistical mechanics, there are far more states in which heat distribution is close to thermodynamic equilibrium than states in which heat is concentrated in small regions, so temperatures will tend to even out over time, reducing the amount of free energy available for conversion to mechanical energy.

Re:Article is wrong. (2, Insightful)

Xiph1980 (944189) | more than 4 years ago | (#31453556)

Having a material direct heat in 1 direction doesn't necessarily result in a perpetuum mobile. If said material only conducts heat from point 1 to point 2 if t1 > t2, and doesn't direct any heat in any direction if t1 t2, then it wouldn't break any law of thermodynamics.

Re:Article is wrong. (2, Informative)

Shin-LaC (1333529) | more than 4 years ago | (#31452956)

It's not wrong, it's just using a more technical definition of "direction" than the one you're used to. In the mathematics and physics I was taught, a vector has three attributes: a magnitude, which is a positive number; a direction, which is similar to a line, not a ray (eg north-south, not just north; the x axis, not just positive x; etc.); and a third thing which determines which way it's going along that direction (a single bit, basically); I'm not sure what this last thing is called in English, so let's call it sign, since you typically decide which way is positive and which way is negative along a direction, and then a signed number gives you both the magnitude and the sign.

This definition of "direction" may seem counterintuive at first, but it's really quite useful, because in physics you often encounter things which have to do with a direction in this sense (as is the case with this new material). That also explains why the writers of the article used this definition.

Note that you cannot simply use "dimension" in its stead. There are three dimensions in three-dimensional space (by definition), but infinite directions, so it's clear that they cannot be the same thing.

Re:Article is wrong. (1)

clone53421 (1310749) | more than 4 years ago | (#31453816)

The magnitude and direction are multiplied together. If the sign is negative, the result is that the direction is negated (opposite): not the same direction anymore.

There are three dimensions in three-dimensional space (by definition), but infinite directions, so it's clear that they cannot be the same thing.

There are infinitely many ways to align those three dimensions. So yes, “dimension” would be correct terminology.

Re:Article is wrong. (1)

Shin-LaC (1333529) | more than 4 years ago | (#31454110)

There are infinitely many ways to align those three dimensions. So yes, “dimension” would be correct terminology.

There are infinitely many *alternative* ways to define three base dimensions, but you can have infinitely many directions within the *same* vector space. Not the same thing.

Re:Article is wrong. (1)

clone53421 (1310749) | more than 4 years ago | (#31454170)

There are infinitely many *alternative* ways to define three base dimensions, but you can have infinitely many directions within the *same* vector space.

Both of those are correct, and neither is contradictory to what I said.

Re:Article is wrong. (1)

ortholattice (175065) | more than 4 years ago | (#31454162)

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.

Right, the article isn't talking about a heat diode [technologyreview.com] .

Re:Article is wrong. (1)

f3r (1653221) | more than 4 years ago | (#31454528)

Direction!=sense (two senses for each direction). Example North-South is a direction, northwards is a sense. That's a difference between colloquial and scientific languages. (i.e. you can tell a friend "I'm heading direction north")

Can't it degrade over time? (1)

madhatter256 (443326) | more than 4 years ago | (#31452622)

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??

Re:Can't it degrade over time? (1)

RaceProUK (1137575) | more than 4 years ago | (#31452642)

In theory, it would expand and contract mostly along the length of the fibres, meaning the wear rate would be much lower. Then again, IANAMS (I am not a materials scientist)

Re:Can't it degrade over time? (5, Funny)

0100010001010011 (652467) | more than 4 years ago | (#31452712)

make it loose its effectiveness??

They include a tiny wrench to tighten it every so often. The first users are suggesting that you should regularly tighten up effectiveness every 400 hours of running.

MIT researchers are currently trying to counteract this self loosening, you may be able to use loctite [henkelna.com]

Re:Can't it degrade over time? (2, Funny)

mcgrew (92797) | more than 4 years ago | (#31453028)

I think he meant loose, as in "loose the dogs of war", rather than loosen. It looses its effectiveness on the heat, maybe? And as it loses its effectiveness it can no longer loose its effectiveness.

Re:Can't it degrade over time? (1, Informative)

Red Flayer (890720) | more than 4 years ago | (#31453126)

I think he meant loose, as in "loose the dogs of war", rather than loosen.

That phrase you're looking for is "let loose the dogs of war".

The verb in that quote is "to let loose", not "to loose".

Re:Can't it degrade over time? (1)

donaggie03 (769758) | more than 4 years ago | (#31453368)

"let loose the dogs of war" can be reworded to "to let the dogs of war loose"
Either way, both "let" and "loose" are verbs here.

Re:Can't it degrade over time? (1)

lawyer boy (152954) | more than 4 years ago | (#31453870)

Actually, I think the phrase is "Cry "Havoc!" and let *slip* the dogs of war. Julius Caesar Act 3, scene 1

Re:Can't it degrade over time? (0)

Anonymous Coward | more than 4 years ago | (#31452816)

Why would the plastic cool down?

Wait, you say you turn off your... oh I see.

Maxwell demon (0)

Anonymous Coward | more than 4 years ago | (#31452644)

Transferring heat in just one direction? So, we can finally boil kettle on an ice cube?

Re:Maxwell demon (2, Interesting)

RaceProUK (1137575) | more than 4 years ago | (#31452670)

While it's not the same technology, wouldn't a Peltier device achieve that?

Re:Maxwell demon (1)

tlhIngan (30335) | more than 4 years ago | (#31452860)

While it's not the same technology, wouldn't a Peltier device achieve that?

No, a Peltier device requires input non-heat energy. No laws of thermodynamics violated. It's just a less efficient heat pump (compared to refridgeration).

Dimension, Not Direction (2, Informative)

camperdave (969942) | more than 4 years ago | (#31452814)

The new process causes the polymer to conduct heat very efficiently in just one direction, unlike metals, which conduct equally well in all directions.

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.

Re:Dimension, Not Direction (1)

Aphoxema (1088507) | more than 4 years ago | (#31452904)

[...] 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.

And the destruction of the Earth! BWAHAHAHAHA!

Re:Dimension, Not Direction (1)

scorp1us (235526) | more than 4 years ago | (#31453214)

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.

Well they would have invented a Maxwell demon at the same time.

Re:Dimension, Not Direction (1)

Mashdar (876825) | more than 4 years ago | (#31454028)

I'm not sure that I actually see a biased thermal potential as totally demonic. Granted I don't see any real-world possibility for it (what is a thermo-phyllic material?), but a thermal bias is not an entropy-beating system if the net thermal change is positive.

Re:Dimension, Not Direction (1)

Zerth (26112) | more than 4 years ago | (#31453760)

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.

And prevent anyone from ever having to endure a warm soft drink. Or hot beverages with the tiniest heat source, given enough time.

Alas, physics.

So no heat diode? (0)

Anonymous Coward | more than 4 years ago | (#31454782)

Damn it, here I was all excited at the prospect of a heat diode.

that explains the heat sink with the new i7 (3, Funny)

gbrandt (113294) | more than 4 years ago | (#31452824)

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

Re:that explains the heat sink with the new i7 (0)

Anonymous Coward | more than 4 years ago | (#31452894)

I guess we'll have contact newegg. It's not like them to leave out such details.

Re:that explains the heat sink with the new i7 (1)

Aphoxema (1088507) | more than 4 years ago | (#31452918)

Everybody thought it was plastic, but it was just new technology.

Uh Duh. New technology is always plastic, then brushed aluminum, then glass. Rinse and repeat.

Re:that explains the heat sink with the new i7 (1)

omnichad (1198475) | more than 4 years ago | (#31453442)

I have a plastic bottle of Pepsi here that says exactly the opposite.

Re:that explains the heat sink with the new i7 (1)

Aphoxema (1088507) | more than 4 years ago | (#31453902)

Pepsi is not new technology. EXTREME energy drinks are, hence they come in brushed aluminum cans.

Re:that explains the heat sink with the new i7 (1)

omnichad (1198475) | more than 4 years ago | (#31454052)

Woosh!
 
When Pepsi was new technology it came in glass bottles. Then, they moved to aluminum cans. Now, they're in plastic.

Not sure how "green" this really is... (0, Offtopic)

ArtFart (578813) | more than 4 years ago | (#31452854)

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.

Re:Not sure how "green" this really is... (0)

Anonymous Coward | more than 4 years ago | (#31454626)

Duh, We just bomb another shithole then, nobody cares, I want my cores cool.

Is it a crystal polymer? (3, Interesting)

La Gris (531858) | more than 4 years ago | (#31452856)

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.

Re:Is it a crystal polymer? (1)

reverseengineer (580922) | more than 4 years ago | (#31453614)

Since there's at least some variability, it might be best to characterize it as having a "high degree of crystallinity." Polyethylene oriented in this way sounds a lot like the ultra-high molecular weight polyethylene fibers marketed as Spectra and Dyneema. Those are made by an extrusion process called gel spinning, and the polymer chains also have a high degree of crystallinity and parallel order. I don't know if the oriented nature of gel-spun UHMWPE fibers is quite at the same level and provides the same thermal properties as ones made by drawing them out with an AFM cantilever, but they might be "good enough," considering that gel spinning is a scalable industrial production method while cantilever drawing is a "very careful scientist" sort of method.

The cantilever drawing method does remind me of making nylon in freshman chemistry lab- you mix hexamethylenediamine and sebacoyl chloride together, and you can carefully pull out a nylon fiber with a stirring rod. Slightly less precise product though.

Re:Is it a crystal polymer? (3, Funny)

CorporateSuit (1319461) | more than 4 years ago | (#31454082)

I don't know if the oriented nature of gel-spun UHMWPE fibers is quite at the same level and provides the same thermal properties as ones made by drawing them out with an AFM cantilever, but they might be "good enough," considering that gel spinning is a scalable industrial production method while cantilever drawing is a "very careful scientist" sort of method.

Well, I have a solution for that. Swap out all the CAPTCHAs on major sites for a webcam peering into an electron microscope that allows a person to draw out the polymer molecules with the cantilever. A week or two, tops, and you'll have someone who's created a bot that can do it perfectly.

Another, similar way is to have Blizzard do the same thing, except using it as a substitute for a CAPTCHA, for every molecule they pull, they get 1 silver piece added to an account of their choice. You'll get the same results, except the bot will speak Chinese.

Re:Is it a crystal polymer? (1)

clone53421 (1310749) | more than 4 years ago | (#31453842)

Straight from Wikipedia, “A crystal or crystalline solid is a solid material, whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions.”

Aligning the polymer molecules in one dimension is not enough. They would have to be aligned in all three dimensions.

Thermal conductivity (4, Informative)

MartinSchou (1360093) | more than 4 years ago | (#31452862)

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: [engineeringtoolbox.com]
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

What about therm interface Re:Thermal conductivity (1)

La Gris (531858) | more than 4 years ago | (#31452978)

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).

Re:What about therm interface Re:Thermal conductiv (3, Informative)

metamechanical (545566) | more than 4 years ago | (#31453100)

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.

Re:Thermal conductivity (1)

Lueseiseki (1189513) | more than 4 years ago | (#31453060)

Best case scenario: 153 W/mK or 61% as conductive as aluminium, 38% as conductive as copper. Not exactly impressive for a heat sink

Maybe they're not as conductive, but polythylene is much, much, cheaper.

No crackheads are going to steal polyethlene from peoples' homes like they do with copper wiring.

Re:Thermal conductivity (0)

Anonymous Coward | more than 4 years ago | (#31453150)

The heat transfer in not by usual thermal conduction, but by an effect involving atomic-force microscope. Therefor the thermal conductivity values are not valid.

Re:Thermal conductivity (0)

LWATCDR (28044) | more than 4 years ago | (#31453262)

I wonder if it might not make for a very good insulator? If it is 300 times as conductive in one dimension is it 300 times less in the other?
If so it could make a very good insulator. You put sheets of it in your wall and it conducts well along the edges but the face would act as in insulator.

Re:Thermal conductivity (4, Informative)

jank1887 (815982) | more than 4 years ago | (#31453482)

don't forget the rest, though:

Density:
copper: 8.96g/cm3
aluminum: 2.7 g/cm3
silicon: 2.33 g/cm3
AluminumNitride (high thermal conductivity insulating ceramic, k~160to190W/mK): 3.33g/cm3

LDPE and HDPE: 0.92-0.97 g/cm3.

So, you're getting a factor of 2-10x in weight savings. Tell that to a aerospace designer and he'll make it work. It's also a cheap material (well, feedstock's cheap. and normal PE is cheap, especially relative to copper these days). Who knows how expensive this stuff might be if they can make more than single fibers.

Re:Thermal conductivity (1)

eggnoglatte (1047660) | more than 4 years ago | (#31454012)

Also, I imagine the 1D heat conductivity has got to be useful for something. It really sounds more like a solid block of heat pipe than a generic heat sink.

Re:Thermal conductivity (1)

reverseengineer (580922) | more than 4 years ago | (#31454166)

The number that gets dropped in the abstract [nature.com] is 104 W/mK. The highly oriented polyethylene fiber Dyneema has a listed thermal conductivity of 20 W/mK [matbase.com] , so this figure would represent a significant advance from the polyethylene fibers currently out there. As you can also see, the "service temperature" for Dyneema tops out at 100C and it melts at about 150C. This new PE fiber with a higher degree of crystallinity would likely bump those numbers up slightly, but it would still be unsuitable for very high temperatures.

Could Help Cheapen Up Spacecraft (4, Interesting)

BJ_Covert_Action (1499847) | more than 4 years ago | (#31452876)

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 [wikipedia.org] 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 [wikipedia.org] 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*

Re:Could Help Cheapen Up Spacecraft (0)

Anonymous Coward | more than 4 years ago | (#31452928)

Don't forget some of that metal is for rad hardening.

Of course when plastic is exposed to heat... (2, Insightful)

Orga (1720130) | more than 4 years ago | (#31452926)

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.

Competitive, but still not better than (1)

metamechanical (545566) | more than 4 years ago | (#31453000)

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 [engineeringtoolbox.com] , 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 [wikipedia.org] .

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.

Re:Competitive, but still not better than (0)

Anonymous Coward | more than 4 years ago | (#31453250)

and between 1/6 and 1/15 that of diamond (900–2,320 W/mK)

A very apt comparison since I only use diamond heat sinks for my gaming machines.

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.

The ability to direct the heat flow can make up for a somewhat lower conductivity for many applications, and can also allow for layouts and applications which wouldn't work with metal heat sinks.

Re:Competitive, but still not better than (2, Informative)

metamechanical (545566) | more than 4 years ago | (#31453558)

and between 1/6 and 1/15 that of diamond (900–2,320 W/mK)

A very apt comparison since I only use diamond heat sinks for my gaming machines.

Diamond is widely considered to be one of if not the most thermally conductive material available. This comparison was included because for those familiar, it is a handy reference. It was as if, because your arms are too short to touch the ceiling, you believe it doesn't matter how high it is.

On a side note, there actually IS diamond thermal paste available for sale [innovationcooling.com] ! Huzzah.

The ability to direct the heat flow can make up for a somewhat lower conductivity for many applications, and can also allow for layouts and applications which wouldn't work with metal heat sinks.

Since the primary issue with metal heat sinks is generally getting the heat wicked off of them, I'd be more apt to consider Finite Element based Thermal Analysis when designing my heat sinks, instead of considering a non isothermal material. That is to say, the problem probably isn't with your material, it's probably with your airflow.

Re:Competitive, but still not better than (1)

ErikZ (55491) | more than 4 years ago | (#31454522)

In it's current state, I'd use it for standard electronics.

Routers, cable modems, etc. Those are encased in plastic already. Making the plastic thermally conductive instead of drilling holes in it for air circulation could be a huge improvement.

Already been done... (1)

rickb928 (945187) | more than 4 years ago | (#31453074)

May be not as effective, but apparently marginally saleable [cnet.com] . the user experience so far has been terrible but that's the way it is with any new [raymond.cc] technology [com.com] .

Now, to make working CPUs out of lead. Solomon's Gold to the rescue!!! Moore's law will be salvaged by modern alchemy!!!

Sure, but... (2, Funny)

Locke2005 (849178) | more than 4 years ago | (#31453326)

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!

Similar to a Niven superconductor (2)

John Whitley (6067) | more than 4 years ago | (#31453564)

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.

AFM is a slow probe (2, Insightful)

Heshler (1191623) | more than 4 years ago | (#31453724)

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.

Re:AFM is a slow probe (1)

Rene S. Hollan (1943) | more than 4 years ago | (#31454668)

Right, but the key part of the article was heat and stretch. There are other ways that this can be done to a plastic. Ever see fresh noodles be made by hand, by a master noodle chef?

The chef starts with a large amount of dough, and draws it out, "bouncing" it on the work surface covered with flour. He/she then folds and twists it upon itself and repeats the process many times: 1 very thick noodle, 2 thick noodles, 4, 8, 16, 32... you get the idea. 10 folds and twists give 1024 noodles (often it's folded upon itself twice at a time, to yield 1, 4, 16, 64 noodles). The flour and gluten content in the dough prevents the individual noodles from coalescing. It's an amazing process to watch. Dragon's beard candy is made in a similar fashion, with sugar.

I wonder if a similar technique could be applied here.

Sounds like Spectra® Fiber to me (1)

DismalTroll (1381731) | more than 4 years ago | (#31454650)

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.
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