backtop


Print 26 comment(s) - last by Fritzr.. on Jul 31 at 11:35 PM


The new cooler design uses copper-coated carbon nanotubes.  (Source: Wikimedia Commons)

It essentially offers a pumpless liquid cooler, which can dissipate massive amounts of heat by boiling the cooling fluid -- water -- in microchannels.  (Source: School of Mechanical Engineering, Purdue University)

Purdue has implemented and tested the nanotech cooler and expects to bring it to market with a few years.  (Source: Purdue University School of Mechanical Engineering)
Forget traditional metal block coolers a nanowick could remove 10 times the heat of current chip designs

A collaboration of university researchers and top industry experts has created a pumpless liquid cooling system that uses nanotechnology to push the limits of past designs.

One fundamental computing problem is that there are only two ways to increase computing power -- increase the speed or add more processing circuits.  Adding more circuits requires advanced chip designs like 3D chips or, more traditionally, die shrinks that are approaching the limits of the laws of physics as applied to current manufacturing approaches.  Meanwhile, speedups are constrained by the fact that increasing chip frequency increases power consumption and heat, as evidence by the gigahertz war that peaked in the Pentium 4 era.

A team led by Suresh V. Garimella, the R. Eugene and Susie E. Goodson Distinguished Professor of Mechanical Engineering at Purdue University, may have a solution to cooling higher frequency chips and power electronics.  His team cooked up a bleeding edge cooler consisting of tiny copper spheres and carbon nanotubes, which wick coolant passively towards hot electronics.

The coolant used is everyday water, which is transferred to an ultrathin "thermal ground plane" -- a flat hollow plate.

The new design can handle an estimated 10 times the heat of current computer chip designs.  That opens the door to higher frequency CPUs and GPUs, but also more efficient electronics in military and electric vehicle applications.

The new design can wick an incredible 550 watts per square centimeter.  Mark North, an engineer with Thermacore comments, "We know the wicking part of the system is working well, so we now need to make sure the rest of the system works."

The design was first verified with computer models made by Gamirella, Jayathi Y. Murthy, a Purdue professor of mechanical engineering, and doctoral student Ram Ranjan.  Purdue mechanical engineering professor Timothy Fisher's team then produced physical nanotubes to implement the cooler and test it in an advanced simulated electronic chamber.

Garimella describes this fused approach of using computer modeling and experimentation hand in hand, stating, "We have validated the models against experiments, and we are conducting further experiments to more fully explore the results of simulations."

Essentially the breakthrough offers pumpless water-cooling, as the design naturally propels the water.  It also uses microfluidics and advanced microchannel research to allow the fluid to fully boil, wicking away far more heat than similar past designs. 

This is enabled by smaller pore size than previous sintered designs.  Sintering is fusing together tiny copper spheres to form a cooling surface.  Garimella comments, "For high drawing power, you need small pores.  The problem is that if you make the pores very fine and densely spaced, the liquid faces a lot of frictional resistance and doesn't want to flow. So the permeability of the wick is also important."

To further improve the design and make the pores even smaller the team used 50-nm copper coated carbon nanotubes.

The research was published in this month's edition of the peer-reviewed journal International Journal of Heat and Mass Transfer.

Raytheon Co. is helping design the new cooler.  Besides Purdue, Thermacore Inc. and Georgia Tech Research Institute are also aiding the research, which is funded by a Defense Advanced Research Projects Agency (DARPA) grant.  The team says they expect commercial coolers utilizing the tech to hit the market within a few years.  Given that commercial cooling companies (Thermacore, Raytheon) were involved, there's credibility in that estimate.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

Help me understand...
By KillerNoodle on 7/27/2010 9:08:01 AM , Rating: 2
The thermal conductivity of Single Wall Nanotubes (SWNT) is aproximately "6600 W/m K for an isolated (10, 10) nanotube at
room temperature,"
Source: http://www.pa.msu.edu/cmp/csc/eprint/DT130.pdf

This is the thermal conductivity along a single SWNT...So how is 550 W/(cm*cm) an improvement?




RE: Help me understand...
By MrTeal on 7/27/2010 10:10:45 AM , Rating: 2
The numbers you give are completely different quantities. One is thermal conductivity in Watts per meter Kelvin, the other is not really a formal unit, it's just power dissipated per unit area. It's kind of a useless measurement since it doesn't indicate the heat delta.

But yeah, if you assume a 1cmx1cm area, and if you have to move the heat 1cm up from the surface of the chip, that's
[(6600W/mK)*0.01m*0.01m/0.01m], or 66W/k for the number you quoted. IE, you can move 66W of heat per degree of temperature difference. Start adding in some interface losses, and it seems like a pretty good number they posted.


RE: Help me understand...
By MrTeal on 7/27/2010 10:17:25 AM , Rating: 5
I should probably also point out that, if one reads the article, they aren't actually using the CNTs as a bulk transfer medium. The system is basically a traditional heat pipe design, but with a smaller pipe size that's stuffed with copper coated CNTs.

Not that I can blame anyone for not reading the original article, it takes awhile to find the damned thing when you have to mouse over 20 links to find the one that doesn't link back to another DailyTech article. How about placing the original article in the subheading or footer of every post so that we can find it, DT?


RE: Help me understand...
By KillerNoodle on 7/27/2010 10:56:37 AM , Rating: 2
WOW...After reading the original article I understand how they are using nanotubes....They aren't . They are using particles of copper bonded to one another not copper coated nanotubes.

The only mention of nano in the article is the authors' institution of research.

This article seems to be an evaluation of a pore size's ability to evaporate a fluid, in this case water.


RE: Help me understand...
By MrTeal on 7/27/2010 11:13:50 AM , Rating: 2
quote:
The researchers are creating smaller pores by "nanostructuring" the material with carbon nanotubes, which have a diameter of about 50 nanometers, or billionths of a meter. However, carbon nanotubes are naturally hydrophobic, hindering their wicking ability, so they were coated with copper using a device called an electron beam evaporator.


quote:
The carbon nanotubes were produced and studied at the university's Birck Nanotechnology Center in work led by mechanical engineering professor Timothy Fisher.


My impression was that they actually are using carbon nanotubes in their test setup, not so much for the properties of CNTs as much as their nano-ness. They're just using them to get the small feature size they need to get really strong wicking. It's hard to tell even from the original article, though. You'd probably have to read the actual journal article to get a better idea.


RE: Help me understand...
By KillerNoodle on 7/27/2010 11:22:19 AM , Rating: 2
When you said original article I thought you meant the journal article so that is what I was reading when I commented about not using nanotubes. The last link in the DT article takes you to the published journal article.


RE: Help me understand...
By KillerNoodle on 7/27/2010 11:42:16 AM , Rating: 2
Just read the Purdue press release... http://www.purdue.edu/newsroom/research/2010/10072...

I really am lost now as to where the nanotubes are coming into play.

The press release talks about nanotubes and says that
quote:
The findings are detailed in a research paper appearing online this month in the International Journal of Heat and Mass Transfer and will be published in the journal's September issue. The paper was written by mechanical engineering doctoral student Justin Weibel, Garimella and Mark North, an engineer with Thermacore, a producer of commercial heat pipes located in Lancaster, Pa.

But the journal article referenced says nothing about nanotubes.

Are they getting their research mixed up?


RE: Help me understand...
By DanNeely on 7/27/2010 10:12:44 AM , Rating: 2
First guess would be that the macro properties don't scale to match the properties of a singe nanotube.


Peltier cell
By kontorotsui on 7/27/2010 8:27:57 AM , Rating: 2
So what is difference between this new design and a peltier cell?

It might more efficient than solid state thermoelectric in removing heat, peltier cell are notoriusly not very efficient, but still you have to sink this heat somewhere and somehow.




RE: Peltier cell
By invidious on 7/27/2010 8:39:09 AM , Rating: 2
I think its closer to a phase cooling system than a peltier system. Your right you would still need a heatsink, but phase change is definitely more efficient than solid state heat pumping. Solid state heat pumping usually creates more heat than it moves. It looks like this might be able to fit a phase cooling system in the size package that we are used to seeing a peltier system, which would be interesting. I wonder if it requires any external power source.


RE: Peltier cell
By DanNeely on 7/27/2010 10:15:59 AM , Rating: 2
If that's the best model it's probably not going to gain any ground in the consumer market, because like water cooling it's going to end up too fiddly. If it can work as a sealed, self contained unit like heatpipes OTOH we could see some really nice gains.


RE: Peltier cell
By SilentSin on 7/27/2010 11:03:13 AM , Rating: 2
This actually does sound like a new flavor of heatpipe rather than some sort of exotic sub-ambient cooling solution. I wouldn't weigh too much on that lab pic as that is just a demo unit for debugging and testing purposes I'm sure.

When he talks about sintered designs and wicks he is talking about stuff already inside your computer most likely. Check out this article for pics of the most often used heatpipe structures of today: http://www.frostytech.com/articleview.cfm?articleI...

I'm not sure of the physics behind "nanowicking", but as Sanity said this wouldn't make much sense if the system had to reach 100C to boil water in order to get the coolant moving. I would assume some type of alcohol mixture would be used for consumer grade sinks or maybe lower the pressure in the pipes so it can boil more readily.

Just seems like a super heatpipe to me but it's definitely a more efficient design than what we use now so the improvements could be drastic. Now we just have to play the waiting game like with other nanotech. All these sweet applications for nanotubes but where are the products you can actually buy that use them...


RE: Peltier cell
By murray13 on 7/27/2010 12:12:52 PM , Rating: 3
Wow, you people really have no clue how ALL heatpipes work.

Air is evacuated so that the boiling point of the water is lowered. How much they evacuate sets the boiling point. That's why some coolers work better on overclocked, high temperature processors, than they do on just a standard load.

And Yes this new development is in the wick structure inside of the heatpipe. Where smaller is better.


Small Mistake
By solarrocker on 7/27/2010 7:33:57 AM , Rating: 4
English is not my first language but shouldn't below say "within a few years."?

"Purdue has implemented and tested the nanotech cooler and expects to bring it to market with a few years. "




RE: Small Mistake
By FS on 7/27/2010 2:37:11 PM , Rating: 2
English is my 5th language and I think you're right.


RE: Small Mistake
By ThisSpaceForRent on 7/27/2010 6:57:29 PM , Rating: 2
That's why English is such a great langauge! You simply words the beat submission into. Proper syntax you need not. Brains people's the blanks fill in.

Could always be the public education in this country though...


More Speed..Lots of Waste Heat!
By Ohmniscient1 on 7/27/2010 12:32:54 PM , Rating: 2
Clever advancement but... made with CNT's?
So does this mean we could run processors 5X faster and produce enough heat to run a small stirling generator or micro steam turbine and recover some the waste heat?
Might make for a noisey PC or Server.. or put in a layer of Direct Thermal Conversion
http://www.avsusergroups.org/tfug_pdfs/2008_2shako...
Hmm...
There has to be a way to run processors faster without wasting all this energy?
Skip all this Silicon heat..
Carbon can be used in a better way.
When do we get the Graphene processors?

http://www.pcworld.com/article/188656/ibm_details_...

Hurry up already..100GHz would be sweet on my PC!




By KillerNoodle on 7/27/2010 12:46:15 PM , Rating: 2
If you are going to use carbon go the whole 9 and use diamonds since they are great thermal conductors? Hence the nick name "ICE".

Someone is working out there to make lab created diamond wafers.


RE: More Speed..Lots of Waste Heat!
By Fritzr on 7/31/2010 11:35:28 PM , Rating: 2
Follow this Google search. Stirling Cycle is useful anywhere there is a temperature gradient, so it is easy to design a CPU powered CPU cooler as well as a variety of other heat powered coolers

http://www.google.com/search?client=opera&rls=en&q...


I Want!
By MindParadox on 7/27/2010 5:57:34 AM , Rating: 2
Make a cooling block for the CPU GPU and Northbridge of a system, ill test it! :)




RE: I Want!
By YashBudini on 7/27/2010 11:43:00 PM , Rating: 2
Yeah, the overclocking crowd will make good use of this stuff.


Just Curious
By Sanity on 7/27/2010 9:59:57 AM , Rating: 2
But from the article it sounds like the cooling device will work by boiling water. Wouldn't this mean that the processor will be at at least 212 F? Unless they had the system under negative pressure so it could boil at a lower temp. Is 212 F/100 C an acceptable temperature to keep your processor?




RE: Just Curious
By ahar on 7/27/2010 12:03:55 PM , Rating: 2
Reducing the pressure seems likely to me. Sapphire do that with their Vapor-X graphics card coolers.
From their site:
"...because the chamber is evacuated to a very low pressure, the vaporisation process occurs at a much lower temperature than normal boiling point."


Good article, stick to easy things.
By NubWobble on 7/27/10, Rating: -1
RE: Good article, stick to easy things.
By tng on 7/27/2010 11:57:06 AM , Rating: 2
Troll, Mick seems much superior to you in every way.....

Since we don't know what your day job is (or even if you have moved out of your mothers basement yet) other than to post comments on other peoples work, you should log off and go away.....


By YashBudini on 7/27/2010 11:41:30 PM , Rating: 1
This is worse than trolling. No need to insult trolls this severely.

For some treating everyone with respect automatically makes them anti-US. You can't argue with those people, they're in their own private Idaho. And loving it.


"Google fired a shot heard 'round the world, and now a second American company has answered the call to defend the rights of the Chinese people." -- Rep. Christopher H. Smith (R-N.J.)














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki