anvilmark writes "ABCNews has an article about a new carbon based thermal conducting foam. Very pricey to produce but has 4-5 times the efficiency of copper at 1/5th the weight of aluminum. ORNL technical documentation available here and here. Sounds like the perfect heat sink shim to me."
Great heat pipe material
by
vought
·
· Score: 4, Interesting
You could make a nicely-shaped heat pipe with this stuff, tranferring heat from say, a processor to the outside of the case easily. I'm sure hardware and environmental engineers will have a ball with this stuff if it can be produced relatively inexpensively.
Research and development
by
reflexreaction
·
· Score: 5, Insightful
Klett admits that it is highly unlikely the foam will break out of the lab and into widely available commercial applications anytime soon.
Stories like this have always annoyed me. You always hear about the possible development of an item that is four or five (or however many years) away from being put into commercial application but after that you never hear about it. Or if it is used commerically you never hear about where it has been put into use. I work in the scientific field and I almost never hear about an exciting development after it's initial announcement.
The one exception to this is pixie dust that has allowed for the phenomeonal growth of hard drives. Oh well.
--
We had to destroy the sig to save the sig.
Re:Goofy comparisons
by
GigsVT
·
· Score: 4, Informative
Uh, wrong, try again.
Where did you find this "fact", the encyclopedia retardica?
Alumina, i.e. sapphires et al, have high thermal conductivity, and yet are almost total insulators. QED.
Please, please, try to check your facts. We all make mistakes, but I have seen so many totally wrong posts in this article that it is depressing me.
-- I've had enough abrasive sigs. Kittens are cute and fuzzy.
I am utterly amazed....
by
dr_db
·
· Score: 5, Informative
That so many posters confuse a heat conductor with a heat pump.
Come on - this will not be "keeping your fridge colder" or "cooling your drinks". It will just make whatever it's attached to move to the ambient temperature faster. Wrap it around your fridge and you will have sour cream in your milk, etc. Or else the coldest kitchen around.
Either it's a brain dead friday, or the collective IQ of Slashdot is lower than I assumed over the last few years.
Re:I am utterly amazed....
by
AnalogBoy
·
· Score: 4, Insightful
The collective IQ has dropped significantly. About now, the 2nd generation of slashdotters are making their exodus to other news sites - or - worse - the real world. By leaving the collective and making the ratio of clue decreases, leaving the bottom-rung stallmanite slashdrones to pick up the slack, so to speak. in addition the average age is now lower.
Perhaps we should charter a report on slashdot groupthink. if i were in college i'd do it.
Alternately, i accept the idea that it is indeed brainded friday.
[Disclaimer - Due to the extraction of a wisdom tooth today and the subsequent mind-numbing hydrocodone, i do not claim responsibility for the content or readability of my above post. It makes sense as i type it. thats all that matters. =) ]
carbon based thermal conducting foam, huh? I wonder if I can encase someone in this stuff and hang em up on the wall in my desert palace...
-- Don't trust a bull's horn, a doberman's tooth, a runaway horse or me.
Re:Not all that hot...
by
jmichaelg
·
· Score: 4, Informative
....PURE copper runs 350-400 W/m-K...pure copper isn't usually used, an alloy is.
I was talking about copper alloys. At room temperature, Both copper 110 and 101 alloys have a thermal conductivity of 391 W/m-k. Phosphorous laced copper alloys will drop you down to around 380. The only reason I happen to have these numbers is I'm currently working on a heat sink.
The news article that got this thread going had so many inaccuracies that I'm prone to think that a marketeer at Poco got somebody at ABC News all excited with hype. Given the foam's poor thermal conductivity, I seriously doubt the national security agency is using it as a heat sink unless, possibly, it's on a satellite. But if that were the case, Poco would have been nda'd and the story wouldn't have made light of day. The story smells of marketeer-speak.
You're right about the density uneveness. There are several elemental foams available that have very uniform density. You can get metal silver foams for applications where surface area is very important. John Carnack (of doom fame) has been playing around with silver foams as a catalyst for hydrogen peroxide to drive his rocket.
However, as a heatsink, foams don't fare well because heat transfer is partially a function, not of surface area as you assert, but of the cross-sectional area perpendicular to heat flow. Foams have lots of surface area which is nice for catalysts but have lousy cross-sectional areas which is what is needed to transfer heat from one edge of the foam to the other. Once the heat is spread out over a heatsink's mass, THEN the heatsink's surface area comes into play. Foams suffer as heatsinks because they can't move heat well from the primary hot spot to their extremeties.
Having said all that, there's some experimental work going on with carbon heat sinks that are configured in standard heatsink geometries. Anandtech's Cebit report shows a few pictures of some carbon heatsinks. Carbon is attractive, because as an element, it does show promise. As a working material, it's difficult. If carbon nanotubes ever get out of the lab, there'll be a huge change - they've got great thermal conductivity - somewhere in the thousands of watts.
Slashdot Mirror
You could make a nicely-shaped heat pipe with this stuff, tranferring heat from say, a processor to the outside of the case easily. I'm sure hardware and environmental engineers will have a ball with this stuff if it can be produced relatively inexpensively.
Klett admits that it is highly unlikely the foam will break out of the lab and into widely available commercial applications anytime soon.
Stories like this have always annoyed me. You always hear about the possible development of an item that is four or five (or however many years) away from being put into commercial application but after that you never hear about it. Or if it is used commerically you never hear about where it has been put into use. I work in the scientific field and I almost never hear about an exciting development after it's initial announcement.
The one exception to this is pixie dust that has allowed for the phenomeonal growth of hard drives. Oh well.
We had to destroy the sig to save the sig.
Uh, wrong, try again.
Where did you find this "fact", the encyclopedia retardica?
Alumina, i.e. sapphires et al, have high thermal conductivity, and yet are almost total insulators. QED.
Please, please, try to check your facts. We all make mistakes, but I have seen so many totally wrong posts in this article that it is depressing me.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
That so many posters confuse a heat conductor with a heat pump.
Come on - this will not be "keeping your fridge colder" or "cooling your drinks". It will just make whatever it's attached to move to the ambient temperature faster. Wrap it around your fridge and you will have sour cream in your milk, etc. Or else the coldest kitchen around.
Either it's a brain dead friday, or the collective IQ of Slashdot is lower than I assumed over the last few years.
carbon based thermal conducting foam, huh? I wonder if I can encase someone in this stuff and hang em up on the wall in my desert palace...
Don't trust a bull's horn, a doberman's tooth, a runaway horse or me.
....PURE copper runs 350-400 W/m-K...pure copper isn't usually used, an alloy is.
I was talking about copper alloys. At room temperature, Both copper 110 and 101 alloys have a thermal conductivity of 391 W/m-k. Phosphorous laced copper alloys will drop you down to around 380. The only reason I happen to have these numbers is I'm currently working on a heat sink.
The news article that got this thread going had so many inaccuracies that I'm prone to think that a marketeer at Poco got somebody at ABC News all excited with hype. Given the foam's poor thermal conductivity, I seriously doubt the national security agency is using it as a heat sink unless, possibly, it's on a satellite. But if that were the case, Poco would have been nda'd and the story wouldn't have made light of day. The story smells of marketeer-speak.
You're right about the density uneveness. There are several elemental foams available that have very uniform density. You can get metal silver foams for applications where surface area is very important. John Carnack (of doom fame) has been playing around with silver foams as a catalyst for hydrogen peroxide to drive his rocket.
However, as a heatsink, foams don't fare well because heat transfer is partially a function, not of surface area as you assert, but of the cross-sectional area perpendicular to heat flow. Foams have lots of surface area which is nice for catalysts but have lousy cross-sectional areas which is what is needed to transfer heat from one edge of the foam to the other. Once the heat is spread out over a heatsink's mass, THEN the heatsink's surface area comes into play. Foams suffer as heatsinks because they can't move heat well from the primary hot spot to their extremeties.
Having said all that, there's some experimental work going on with carbon heat sinks that are configured in standard heatsink geometries. Anandtech's Cebit report shows a few pictures of some carbon heatsinks. Carbon is attractive, because as an element, it does show promise. As a working material, it's difficult. If carbon nanotubes ever get out of the lab, there'll be a huge change - they've got great thermal conductivity - somewhere in the thousands of watts.