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New Semiconductor Coolers 161

Posted by CmdrTaco from the now-that's-a-lotta-cooling dept.
An anonymous reader writes: "A new thermoelectric material is 2.4X as efficient as best existing materials. The new solid state heat pumps can provide 700 watts of cooling (nearly one horsepower) with just one square centimeter. These new materials have the potential to replace current heat sinks, thermoelectric generators and mechanical heat pumps. You can also read an article in nature."
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New Semiconductor Coolers More

New Semiconductor Coolers

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  • In one word... (Score:4, Funny)

    by codeButcher ( 223668 ) on Wednesday October 17, 2001 @09:36AM (#2441153)
    cool!

  • Great..... (Score:1, Flamebait)

    by spagma ( 514837 )
    Now it will only take about a square foot of this new material to cool the Pentium 4 processors.

    • Re:Great..... (Score:1, Flamebait)

      by kirkb ( 158552 )
      Kudos on whoring for karma using the tried and true "Bash M$ or Intel" technique. The slashbot mods always fall for that one.


      FYI - An Intel P4-1.5ghz puts out 52watts, while an AMD Athlon-1.33ghz emits 73watts. Almost fifty percent more!

      • What do I care about Karma anyway, it doesn't make me sleep any better at night. If you thought it was funny, fine, great. If you took it personal, then kiss my ass. In fact, I am sure I am sacraficing the everloving Karma now, by telling to to go fück yourself. So take your stats, cram them up your ass, and you can see how may watts that emits!

  • What I am wondering (Score:2, Interesting)

    by Sycraft-fu ( 314770 )
    Is if it is more efficient in terms of output/input or just more efficient in terms of output/area. Heat pumps are nifty little devices, but I seem to recall that the ones we messed with in physics class weren't terribly enegry efficient. I'd be interested to know if these new ones are a little better.

    All the same, they sounds like fun things for extreme overclocking.

    • The questions in my mind that the articles didn't (and seemingly never) address:

      1) How long until I can go pick one up?
      2) How many patents are going to keep the price of this sky high for the next 20 years?

      • Well, since the research was funded by the government (DARPA and ONR) and RTI is suppose to be a nonprofit organization, I would think the patents are already in the public domain or at the very least have very affordible licensing.

      • It's not the patents that will keep the price sky high. Follow the links down to the actual scientific publications and think about what it takes to make such a material...
    • From the article:


      The new materials are almost as efficient as
      mechanical heat pump systems, but for applications such as refrigerators and home heat pumps, the cost must come down.

    • Re:What I am wondering (Score:3, Informative)

      by atrowe ( 209484 )
      The problem with these heat pumps (and Peltier coolers) is that the cooler sucks heat away from the processor side and pushes it to the exposed side of the cooler. As an unfortunate side effect, the cooler GENERATES additional heat in the process.

      As an example, if your processor generates 50 watts of heat output, the cooler might generate an additional 50. The processor itself would stay cool, but you're dumping a lot of extra heat into your case, requiring even more case ventilation.

      Not very practical for most users.
      • Indeed. And given that it has the "potential"
        to sustain up to 700 W per sq cm, the efficiency
        of the device is questionable.

        Who wants to have a 50 W processor and use an
        additional 50-500 W to cool it? Faster processors, yes, but your case turns into a
        space heater.
        • The impression I got from reading the article was that this device would generate up to 700W of electricity on its output lines (by converting the heat into electricity), and it would only require electricity input if you wanted to heat the target device
      • Tingler- Dictionary-carrying English [dictionary.com] speaker. I have no tolerance for poor spelling.
      • ---Not very practical for most users.

        Depends, I know several research grade CCD manufactures who would sell a first child for a better Peltier.

        If you need to cool a small device (like a CCD camera) to -100 C you can stack several Peltiers or cool with LN.

        It's all about signal to noise, how much noise can you tolerate.

        TastesLikeHerringFlavoredChicken
  • Are the geeks going to gather around them and gossip?

  • NPR information (Score:4, Informative)

    by queequeg1 ( 180099 ) on Wednesday October 17, 2001 @09:40AM (#2441172)
    There was a brief bit on NPR about this a few days ago. NPR recording [npr.org]

  • Can we get rid of the fan though? (Score:4, Insightful)

    by hattig ( 47930 ) on Wednesday October 17, 2001 @09:40AM (#2441177) Journal
    With a suitably sized heatsink made of this material, can we get rid of the noisy fan, or at least replace it with a slower, quieter fan.

    This would be great for those of us with 1.4GHz Athlons rumbling away in the corner.

    I expect that it will start of as some kind of heat spreader material on CPUs themselves, and possibly in the base plate of the heatsink. It is probably very expensive.

    Itanium will need a tonne of the stuff... :)

    • Re:Can we get rid of the fan though? (Score:4, Insightful)

      by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Wednesday October 17, 2001 @09:57AM (#2441253) Homepage Journal
      With a suitably sized heatsink made of this material, can we get rid of the noisy fan, or at least replace it with a slower, quieter fan.

      You're missing the point; We don't make heat sinks out of peltier junctions, we put them on top of peltier junctions. In order to keep the heat sink cool, we put a fan on them.

      In other words, we will never make heat sinks out of this material. We'll simply transfer heat to them with it. Current heat sinks work fine.

    • No, we can't get rid of the fan.

      The reason for this is we still need to be able to keep a reasonable temperature to reject heat TO. That is, the heat sink is worthless if we haven't some lower T source. If we could transfer heat from a cold source to a hot one, we'd have a perpetual motion machine. Hence, we need to run air across the heat sink to matain this temperature gradient.

      As a side note, the temperature gradient is what defines the work done (or dissipated) from the heatsink. So the heatsink becomes more efficient as the gradient increases (n=1-(Qc/Qh) for a Carnot engine).

      This is why, also, car engines become less efficient when temperature increases. Also, if the temperature at the tailpipe of your car was the same as that of the combustion, you wouldn't be able to drive the car; there would be no power. You'd also melt by that point, but that's another story.
      • Thanks for an answer with reason in it.

        The article inferred that you could generate electricity by using the device, but it seems that you can EITHER apply electricity to cool/heat something, or gain electricity by some other means which was never made clear.

        So in the end, you need this material on your die, a heatsink on top that can deal with ~2x the heat that the CPU would be putting out, and a fan to cool the heatsink. The important thing is that the heat is being removed from the CPU damn quickly and efficiently, and being moved a millimeter or two higher... I think.

    • This would be great for those of us with 1.4GHz Athlons rumbling away in the corner.

      Athlons don't rumble. If you have the money to buy a heatsink made of this new material you have the money to buy a NoiseControl Silverado. They're 86 bucks with shipping when you get them imported. They're silent and cool. http://www6.tomshardware.com/cpu/01q2/010521/coole r-29.html for more info.

  • Sure, it's a hoax [demon.co.uk], but nothing else will suffice.
    Although Peltier cooling [arstechnica.com] is pretty nifty, too.
  • I wonder if these could be put into various locations in heatsinks to allow more efficient dispersal of the heat throughout the entire structure (and from there, pure passive dispersal - no fans).
    • An IMac has no fan. The CRT is hot enough to generate a significant draft. Thus convective cooling is adequate. Last I heard, the IMac motherboard is essentially a laptop motherboard.

      There used to be all-in-one PCs with convective cooling, but someone used FUD advertising to run them out of business.

      I'd like to have my PC's sound card hooked up to my main home stereo, but it's too noisy. I did bring down the noise by replacing the fans.

      • Yeah, I've been on a quest to quiet down my PC for some time now... I am a bit of an audiophile, and I use high-bitrate MP3s in addition to my CD player, so I would like my PC to be silent. The straw that broke the camel's back on this one was the 40GB Maxtor drive that I bought, which was audible through the telephone.
        So I ordered a power supply, heatsink, and drive enclosure from Quiet PC [quietpc.com]. That fixed things to about 90% of what I would like... big improvement. But it is still an aftermarket fix for something that is admittedly broken w.r.t. sound emission.
        It's great to see sound finally being considered by the industry... for example, the current trend in hard drives is FDB (Fluid Dynamic Bearings), which allows idle noise from the drive to be in the ~30dB range... and I seem to recall a post here recently about Dell P4 systems being very quiet.

  • One word: (Score:1, Offtopic)

    by smaughster ( 227985 )
    Cool!

  • More Links (Score:5, Informative)

    by Alien54 ( 180860 ) on Wednesday October 17, 2001 @09:47AM (#2441210) Journal
    On the nature site, they also have full text with all the gory scientific details [nature.com], and a PDF.

    a couple of them in fact. (look to the bottom of the page)

  • Humor Yes Good news But kindly dont be too happy...news from the black labs of intel is that they are going full steam to make sure the new pentiums evaporate these johnny come lately heat conductors or whatever those idiot /.ies call them. End Humor PS:these above tags are for those highly honourable moderators who cant distinguish between an attempt at humor and a troll....
  • So now with this new device CPUs can run Cooler thus allowing a higher MHZ per chip and allowes more overclocking. So wont this extend the MHZ myth and make lousy chip chip desing going for a while longer atleat untill the chip are used in replacement for heating coils for tosters.
    Me personally I am big fan of RISC arcecture it genereally seem to run cooler and with less power plus smooth performace (on most RISC chips)
  • I haven't had a chance to see the article yet - but I know that there was something a bit back (on /.) on this where they designed small "pumps" that cranked the heat off of stuff and they were very good at it - this sounds very similar.

    I suppose I *should* read the article to see.
    • looks like these are not quite the same. what I recalled were carbon rings that, due to their shape, would pipe the heat away up through the tube (very small tube) shape. seemed they moved heated air moreso than conducted the energy directly.
      and I don't recall any application of the energy then being reused, whereas this article seemed to indicate these could do that. very cool.
  • A new thermoelectric material is 2.4X as efficient as best existing materials. The new solid state heat pumps can provide 700 watts of cooling (nearly one horsepower) with just one square centimeter. These new materials have the potential to replace current heat sinks, thermoelectric generators and mechanical heat pumps. Just means more overclocking potential. ;) Hrm. One superconductor, plus a heat sink the size of my car, plus that liquid nitrogen pump, and I might just get Win2k to load in under a minute. Wow.
    • Ok, this is off-topic, but my Win2k box boots just as quickly as my Linux box, and they are machines of comparable performance. Both boot in about a minute and a half. The W2K box is a Duron-700, and the Linux box is a dual Celeron-400. Yet I have heard repeatedly that Win2k is slow-booting.

      What's going on? Is my IBM 7200rpm hard disk really that fast?
      • Consider the source. Win2k is really not terribly slow for most people, but you must take into consideration the attention span of the average Slashdot poster... (not to mention the pedestal that MS products are held on around here)

        :)
      • The W2K box is a Duron-700, and the Linux box is a dual Celeron-400. Yet I have heard repeatedly that Win2k is slow-booting.

        er...you're joking...right? maybe I'm asking too much for a comparison between two *similar* systems? My linux machine is a p200 and it boots in about one minute, while my (p75) w2k machine takes at least two, yet I have heard repeatedly that linux is slow booting...

        I'm not disputing what you are saying, but please, if you have a benchmark, don't even mention it if it isn't on similar hardware.
        • maybe I'm asking too much for a comparison between two *similar* systems?
          I don't understand the problem. Even if the Duron is twice as fast, that would only account for a factor of two in the boot time, and I would still have a hard time seeing how that would be so universally derided as being slow.

          If the comparison bothers you, forget the Celeron. On my Duron-700, W2K takes less than 90 seconds to boot, which seems quite resonable to me.

          please, if you have a benchmark, don't even mention it if it isn't on similar hardware
          I'm sorry my data isn't up to your standards, but it's all I have, and it was never intended to be a benchmark: just a data point. In fact, the numbers are from memory, since I don't boot very often, so the error margin is probably larger than that caused by the differing hardware anyway.

  • A fix at the wrong end (Score:5, Insightful)

    by Junks Jerzey ( 54586 ) on Wednesday October 17, 2001 @09:48AM (#2441219)
    While this is neat and all, I should hope that more effort goes into lower power consumption in general. Just because there's a better way to cool high-power chips doesn't mean that such a chips are a good idea in the first place.

    Someone I know who works in embedded systems recently pointed out that most CPU makers have decided to chase performance at all cost without regard to power consumption, and this is leaving embedded systems engineers up a creek.
    • Someone I know who works in embedded systems recently pointed out that most CPU makers have decided to chase performance at all cost without regard to power consumption, and this is leaving embedded systems engineers up a creek.

      Good thing the P4 and Athlon aren't intended for embedded use, they're intended for use in desktops where power consumption isn't so much of an issue, and in laptops, where it's an issue, but not as big an issue today as it once was, as batteries (while still crappy) have come quite a long way.

      There are plenty of chips/cores which have been optimized for low power use, including SuperH, ARM, TransMeta, and various MIPS cores. There are also many low-power 386 and 486 cores. The fact that the latest and greatest CPUs require a lot of wattage is not unreasonable.

      • There are plenty of chips/cores which have been optimized for low power use, including SuperH, ARM, TransMeta, and various MIPS cores.

        There are fewer than you think. Transmeta is out of the question, because it is too pricey. And even game consoles are starting to include fans and large heat sinks, which is more than a bit crazy.
        • How is that crazy? It just means they're getting more powerful, like real computers. Desktops had a phase when they required no cooling, as did consoles, why should only one ever change?

          • How is that crazy? It just means they're getting more powerful, like real computers. Desktops had a phase when they required no cooling, as did consoles, why should only one ever change?

            Why must more computing power equate to a need for heat sinks? is I think what the parent post is getting at (and I agree).

          • Reliability is one issue. Moving parts make noise and fail early. I've seen a quite a few cpu fans go bad in under a year, and most seem to go bad in under two years.

            > It just means they're getting more powerful, like real computers.

            More speed and computational power doesn't mean more heat and electrical power consumption. Compare ENIAC to modern wristwatches with calculators. More fairly, compare my K6-233 to the 209MHz Strongarm 1110 in my iPAQ.

            Your comment is amusing. What do you mean by "real computers"? I'm guessing that you mean "whatever crap Dell told me is a real computer". That's an uncharitable suggestion, of similar naivite to your comment.

            -Paul Komarek
            • Excuse me? I meant real computer as in commodity desktop. I'm typing this on an Epox 8k7a+ with a tbird 133, Gainward gf3, lian-li pc70, all the usual things you would expect in a computer like this. I built it by hand, after hand-picking each part. Don't accuse me of being a sheep.

              Also, you compare a K6-233 to a Strongarm @ 209, even though they're wildly different architectures from different eras, for different purposes. We have low power CPUs, look at the C3. It just comes at the price of performance. No matter how efficient your chip is, you can make it faster and hotter, and that's what's being done, since most people want it. Deal.

              (avoiding lame filter)

  • FOR IMMEDIATE RELEASE:
    Craig Barrett, 61, Pres, CEO of Intel Corporation was quoted today in a fake press release as saying,

    "This is fantastic! With this new thermoelectric material that is 2.4X as efficient as the best existing materials, we can create processors which run 2.4X as hot! Not only that, but we can repackage all those old Celeron 300a's as Pentium 5's and overclock them 2.4X as much! Lookout AMD, here we come!

  • When cooling fails (Score:5, Funny)

    by jxqvg ( 472961 ) on Wednesday October 17, 2001 @09:50AM (#2441228)
    These things are going to get so efficient and semiconductors running so hot that when one of them fails the whole thing will go critical mass. Your box won't just fail, it'll burst into flames and melt into a useless bubbling pool of metal and plastic!

  • So where does the heat go after it has been 'pumped' away from whatever? - Seams to me that one side of these thermo-electric heat pumps will get quite hot..... I still think there is need for a heat sink to cool the thermocouple so it can keep doing its job.
    • The current generation of commercially available heat pumps is already in use. They use heat sinks to cool the hot side of the wafer, and CPU fans to transfer heat from the heat sink to the air, and, of course, the box has a fan to replace hoter air with room air.

      I've even seen water cooled PCs.

  • Wow this author really does have this thing doing everything. Of course here we only think of cooling our new P4 etc etc. In the article they mention everything from only cooling parts of the chip, cool no need for that huge piece of metal, to controling the temp in the production on RNA and other proteins. Basically this guy is saying that this stuff will cool your PC, cure health problems and save the world. Wow. And I would have just been happy with no fan on my proc.
  • I say we use these things for some REAL heat dispersion: let's cool the engines of those old VW bugs! They're already air-cooled, so now we could totally overrev the things and make Herbie faster than a Ferrari. Yeeha!

  • The material, devised by Rama Venkatasubramanian and co-workers...


    I hope they don't name the devices after the inventor. "Give me a Venta..., a Venkatip..., a Venksubrim..., ah dammit! Just give me a heat sink!"



  • Passing an electric current from one conductor to another can make the interface between them hotter or colder, depending on the direction of the current.


    So.. instead of a fan, can I put a thermoelectric cooler on top of the chip so as to eliminate that noisy, always failing, fan?

    Does this use a huge amount of power as compared to the fan?
  • Considering the design problems inherent in automotive intercooler [gnttype.org] design with trying to balance flow [cthome.net] and cooling efficiency, it would be wonderful to adapt a technology like this to cooling in racing applications. There have been some theories [scuderiaciriani.com] on the best way to approach this in the past, but something like this would be wonderful!

    - Freed

  • Isn't this just a Peltier cooler with improved materials?

  • misleading headline - this GENERATES power (Score:5, Insightful)

    by deander2 ( 26173 ) <public@[ ]ed.org ['ker' in gap]> on Wednesday October 17, 2001 @10:24AM (#2441409) Homepage

    The body of this news item is misleading. This material can GENERATE 700 watts of electricity from only one square cm. (specifically under a 58 degree F tempature gradient).

    It can also heat and cool things 2.5x more efficiently (then anything else on the market) if you push electrons through it, rather than let them come out.

    Very interesting stuff, IMHO. Generating electricity from waste heat with inexpensive materials is a holy grail of sorts in a LOT of applications.

    BTW, this is what the patent system was SUPPOSED to protect. True innovation.
    • This material can GENERATE 700 watts of electricity from only one square cm. (specifically under a 58 degree F tempature gradient).

      there's not enough energy difference in a 58-degree gradient to account for 700W per cc. if this were true, i could power Boston by replacing my oven's door with this stuff & baking a batch of brownies.*


      i exaggerate, but the energy figure given is still ridiculously large.

      • that's what the article says. do you have calculations to prove them wrong?
      • It's not the temperature difference alone that determines the power, but the temperature difference times the heat flow. And I know of no theoretical limits to heat flow, although there are lots of practical problems...

        Nature has the full scientific article. [nature.com] I don't understand most of it, but it does say "Thin-film thermoelements lead to large cooling power densities (PD)... We estimate a value of PD of 700 W cm-2 at 353 K and 585 W cm-2 at 298 K at the measured maximum cooling in superlattice devices compared to a value of 1.9 W cm-2 in the bulk device of Fig. 4a". That is, 700 watts/cm2 cooling at 70C (the max temperature for industrial-spec semiconductors), 585 at 25C (room temperature), and it's about 350 times as fast at pumping heat as the comparison thermoelectric material.

        To actually use that cooling ability, you've got to somehow couple 700W/cm2 heat into one side and remove rather more heat from the other side. (Or to generate 700W power, you've got to couple more than 700W to one side and remove the waste heat from the other.) A TO-220 power transistor has an approximately 1 cm2 metal plate on the back to contact the heatsink; take a really big heatsink and really good thermal paste and really torque down the screw clamping them together, and it will handle almost 20W. 700W would fry the transistor core instantly, before the backplate even got warm. The coupling between a GHz Pentium and heatsink/Peltier refrig/fan must be better than this, but not THAT much better. Lots of luck!

        By the way, anyone notice that the reporter doesn't know the difference between "efficiency" and "effectiveness".
      • You can't convert Temperature directly into power. Temperate is not a measure of heat energy. Just as voltage is not a measure of electric energy.

        A differential of 1 degree could theoretically produce thousands of watts of power, if there is a large enough source of heat. The differential is merely a way of transferring the power.

    • The body of this news item is misleading. This material can GENERATE 700 watts of electricity from only one square cm.
      I'm not sure why you think this. The quote from the article is:
      A thermoelectric module with just one square centimeter of RTI's new material can provide 700 watts of cooling, or nearly one horsepower, under a temperature gradient of 58 degrees F.
  • So, with a mere 700 of these, my computer can out-race a Ferrari F1, by hot air alone.


    Brings a whole new dimension to those stale Beowulf jokes.

  • more on this..... (Score:2, Interesting)

    by dragonxhero ( 524736 )
    some other really cool stuff about this.... first off, the advancements that have taken place haven't made it efficient enough to replace most cooling devices, but if they can double the efficiency they believe they could start making 'solid-state' refrigerators and such.... the other really neat thing about this innovation is that not only does the material cool things down, but if you expose it to heat it generates electricity.... there's supposed to be huge potential there... the example i heard was that the material could be used to regain much of the wasted thermal energy put out by combustion engines, perhaps in a type of hybrid gas/elec car.... -- dragonxhero

  • Idea (Score:3, Interesting)

    by Pyrosz ( 469177 ) <amurrayNO@SPAMstage11.ca> on Wednesday October 17, 2001 @10:33AM (#2441488) Homepage
    Due to the problem of fitting larger heatsinks and fans (damn loud things) onto ever smaller motherboards and chips, is it not time to re-think this idea? Would it not be possible to use this new material to pump the heat from the chip to the side of your case? The side of your case could be a very large heatsink. It would require small fins and might even improve the looks somewhat. It would not get hot due to the surface area and heat dispersion. Why use a small (relative) heatsink and excesivily (sp?) loud fan to cool the chip when you already have a large heat release area? Anyway, just a thought.

    • If the case is a thick piece of aluminum, it does make a pretty good heatsink, except that there is a terrible mechanical issue involved in clamping hot electronic parts to the case for good thermal transfer while still keeping them seated in the socket. I once worked on a plotter where the case lid was the heatsink for the motor drive transistors -- worked on it again and again, because the @#$%^& transistors kept pulling out of their sockets. You really don't want to go through this experience with a 400-pin device...

      The thermoelectric device won't help with this issue. It is just this little disk that gets colder on one side and hotter on the other as you put electricity into it. What it does help with is if heat conduction, which is proportional to temperature difference times area, is insufficient to keep the IC temperature within working limits. That is, the interior of the IC is hotter than the outside, which is hotter than the heatsink, which has to be hotter than the air, and all those temperature differences can add up to a cooked CPU. The Peltier refrigerator changes this relationship by maybe 30 degrees. But you still need the heatsink to be clamped very solidly to the IC, just with the Peltier disk in-between.

      What might work (if you really want that heavy metal case) is to use some sort of flexible heat pipe to connect the CPU and other hot spots to the case. Some laptops sort of do this with a flat plastic bag containing heat-conductive liquid or gel -- they lay it on top of the motherboard, then clamp the case over it, and it spreads the heat from the CPU, etc., out to that whole side of the case.

      For higher heat-carrying capacity, you use a tube containing a substance that evaporates at the hot end and condenses at the cold end, with wick material to move the liquid back to the hot end. This sort of heat pump is usually metallic, but some corrugations in the middle would let it bend a few tenths of an inch. So you can attach the narrow hot end of this thing to the CPU, put the lid on the case, then run screws through it into nuts built into the wide cold end of the heat pipe and tighten it down, and that little bit of bend will allow it to tighten down flat to the underside of the lid without pulling the CPU out of the board...

      • The thermoelectric device won't help with this issue. It is just this little disk that gets colder on one side and hotter on the other as you put electricity into it.


        I figured the hot end of this could touch my case side (big heat sink!)? Of course the motherboards would have to be changed so that the chip was close to the side (top?) of the case.

        Im just really tired of that damn fan noise!
        I already got rid of my power supply fan. I moved the supply to the bottom of my case and opened it up. And I have no case fans anymore. I just cut a few more holes into it.

        • Yeah, Pyrosz it's not that bad an idea, it's just that the mechanical arrangements are quite difficult. For proper heat transfer, surfaces must be flat and touching all over -- thermal grease fills in microscopic valleys, but if you don't clamp things together until only a very thin layer of grease separates the parts, you don't get good heat conduction. So a combined case and heatsink normally means the parts are bolted to the case, and to get it apart they've got to come out of the board. Then there's the problem of tolerance stack-up: nothing is ever exactly the intended size and shape, so when you put it together the pins on the parts miss the sockets...

          Another issue for motherboards is that the CPU is on the same side as the cards, which isn't the side you can put close to the case. This is because bus connectors are soldered by wave solder (shooting a wave of liquid solder onto the bottom side of the board). Small capacitors and resistors can be glued onto the bottom and survive this process, but IC's might not, and you certainly don't want to do it to either a CPU or a socket...

          If you don't have any bus cards or other plug-in parts taller than the CPU, then you could flip the board over and bolt it down with the CPU touching the case. They should be clamped together fairly hard, so you'd have to put holes in the board right around the CPU for bolts, or else put a brace behind it to support that area. And the case has to be unusually thick (at least near the CPU) so it's heat conductivity is enough to spread the heat out.

          Insane as all this sounds, the standard cooling method is a little odd too. We use a good system for cooling a number of warm parts scattered all over (air circulation) and try to make it work to cool one extremely hot part...

          The Peltier refrigerator would make the CPU taller, and allow the thermal interfaces to be not quite so perfect -- it would be a help here, but I'm dubious about it being worth the cost.

          Finally, remember that other parts generate heat too. Not as much as the CPU, but it still has to be removed.
      • The thermoelectric device won't help with this issue. It is just this little disk that gets colder on one side and hotter on the other as you put electricity into it.

        So put the cold side on the processor and the hot side on the heatsink & fan. The efficiency of the heatsink is now much greater, since its rate of heat exchange with the air depends on how much colder the air is. The only problem is how efficient is the thermoelectric component - does it move more heat than it makes? I seem to recall that earlier peltier coolers tended to also have power supply problems (as they took a lot of current (though at relatively low voltages)).
  • The trick is in "stacks of very thin films of two alternating semiconducting materials" Ok, so how thick is this stack. I would imagine that a stack 2CM thick would be capable of collecting twice the energy of a stack 1CM thick. I suppose if we had a stack 7 meters thick it could easily collect 700 watts (assuming the energy was there to collect in the first place.)

    Maybe if we left these out in warm sunlight they would collect energy too? They might be cheaper than photovoltaic cells. (perhaps a layer of photovoltaic with a layer of these behind them might be the ticket?)

  • It can do what now? (Score:3, Insightful)

    by BillyGoatThree ( 324006 ) on Wednesday October 17, 2001 @11:50AM (#2441917)
    "...can provide 700 watts of cooling (nearly one horsepower) with just one square centimeter..."

    Can someone explain exactly what this means? I haven't reach thermodynamics in my physics studies yet.

    I mean, I understand "700 watts"--that's 700 Joules/second. So presumably a cm^2 of this material can "cool" 700 Joules of heat energy every second. But surely the limiting factor here is how quickly the *air* (or other surrounding medium) can *accept* energy, not how fast the device can pump it out....right?

    I saw this same article over at bottomquark except they had a new release linked as well. The release claimed that just a few dots of this material on a chip would replace (plus some!) a regular heat sink. How on earth could that be? What about the areas where dots aren't located?
    • You're exactly right on all the points you raise.

      The only way you'd get 700 W through a 1cm^2
      area is if you placed a highly conductive
      material on one side at a high temperature
      and another highly conductive material at low
      temperature on the other, (like two silver rods)
      and then supplied heat and cooling to the hot
      and cold rods.

      If the hot end were air and the cool end were air,
      you'd have to be blowing hot and cold air with
      hurricane force across the surfaces.

      PM
    • But surely the limiting factor here is how quickly the *air* (or other surrounding medium) can *accept* energy, not how fast the device can pump it out....right?
      Yes and no. Your reasoning is clearly correct as it stands, but you forgot that they specified a certain temperature differential required to attain a 700-watt power dissipation. If the air temperature gains 1 degree, so does the CPU.

      The heat-conducting ability of a cooler is proportional to the temperature differential. Recall that the CPU is hotter than the air. If the air temperature gains 1 degree, the power dissipation temporarily decreases because of the lower differential, causing the CPU temperature to start rising. The rising CPU temperature tends to restore the differential, and eventually the system reaches a new equilibrium with both the CPU and the air at a higher temperature. Eventually, the air gets so hot that whatever pitiful circulation it has is enough to remove the 700 watts of heat (though if properly insulated, the CPU could melt first).

      If you're familiar with electricity, think of heat as current and temperature as voltage. A cooler, then, provides a thermal resistance (and the lower the better).

      The release claimed that just a few dots of this material on a chip would replace (plus some!) a regular heat sink. How on earth could that be? What about the areas where dots aren't located?
      Presumably the silicon itself would conduct that heat to the areas where the does are located. Or perhaps the heat would be conducted straight into the packaging material. Whatever happens, it doesn't matter much because, by definition, those areas aren't producing much hear.
    • I mean, I understand "700 watts"--that's 700 Joules/second. So presumably a cm^2 of this material can "cool" 700 Joules of heat energy every second. But surely the limiting factor here is how quickly the *air* (or other surrounding medium) can *accept* energy, not how fast the device can pump it out....right?

      The two rates (heat in and heat out) are equal. Otherwise the thermoelectric gets hotter, and hotter, and... The way the TE works is by driving a current across a junction of two different materials. This creates a thermal interface where heat can be exchanged very rapidly. This means the side of the TE in contact with the processor cools down, so that heat is transferred faster from the processor.

      Of course, you are putting energy into the TE device in the form of electric current, and this energy must also go somewhere. Therefore the hot side of the TE becomes very hot indeed, hotter than the surface of the processor. This higher temperature gradient allows the heat to be dropped to the surrounding air faster that an ordinary heatsink.

      Some people have been saying this device produces power. This is not correct; the device is a power sink, and that power is ultimately converted to heat. The real question is, when the device is operating at full transfer capacity of 700W, how much power is it drawing itself?

      Ultimately, this scheme requires more power, placing more stress on your power supply and burning more fossil fuel. I'd be much more excited to see a Plain Old Heatsink that could transfer at 700W.

    • Yes, good, the rate at which energy is carried away from the other side is a limiting factor. The reason you might want to apply it to only specific areas is that this is very strange material, and very expensive to produce.

      The key in these materials is that they conduct electricity very well, but conduct heat poorly. This is weird, as the two are usually linked. The electrons carry heat energy with them as they move through the crystal, and the random motions of the atoms transfer heat through the crystal as well. The electrons and the vibrations (phonons) interact, hence the link between the two kinds of heat conduction. You usually only hear about the atomic vibrations because that effect is many thousands of times stronger than the electronic heat conduction.

      However, we can control the motion of the electrons. We cannot control the flow of the heat transfered by the random motion of atoms. The big idea is to create a material that impedes the flow of heat, but allows us to control the flow of electrons. As bizarre as this sounds, there are some naturally occurring minerals that have this property (skutterudites). These are exremely rare, and harder to synthesize than diamonds. There are strategies involving alternating layers of semiconductor, and that sounds like the plan in this article.

      The point is that these materials are hard to make, and very expensive (high purity, many production steps). It turns out that only some parts of an IC generate huge amounts of heat (this is an issue when we mount optical devices on ICs). The dot idea is a clever trick to save on production costs. Those clever engineers.

    • Re:It can do what now? (Score:3, Informative)

      by WNight ( 23683 )
      I agree with your conclusions.

      This seems like a great way to quickly remove heat from a small area and spread it to a large area. You'll still have a lot of waste heat on the hot side of this and I'm sure you'll need a heatsink on there. Large than before in fact because this appears to be a powered thermocouple like a Peltier cooler which means it should generate waste heat as well.

      The benefit though is that heatsinks become more efficient as the temperature gradient goes up, so we should still be able to get the heat into the air and then out of the case. And because this thermocouple maintains a rather large gradient we should be able to keep the CPU that much cooler.

      As for the little dots of it, etc... I think what they mean is that inside the CPU core you'd have little dots of this being used to pump heat away from the main heat generating areas directly into the heat-spreader on top of the chip. The only other way to do it is let the heat diffuse through the whole core and then into the heat spreader.

      So this would be a lot better at putting heat in manageable areas (the heatsink) but it isn't magic, you couldn't put a bit in a sealed package and have heat magically disappear.
  • Could this be used to eliminate the steam turbine stage in nuclear (electric) power generators? Might be more efficient and surely safer as long as there is some way to buffer in case of a sudden huge drop in demand for the output.
  • What I want to know is when will we see this technology in chip manufacturing, etc?

  • Thermoelectric + Photovoltaic = Higher Output? (Score:1, Interesting)

    by Anonymous Coward
    Since photovoltaic cells produce less energy the warmer they become, is it possible to combine the two?

    A thermoelectric photovoltaic power cell. The thermoelectric keeps the cell cool, and provides some power, and the photovoltaic cell operates at a more optimum, efficient temperature.
  • I wonder if this technology could be used to create a solid state engine. If you think about it, when you burn fuel in your engine, you're turning the heat energy into horsepower, which is what this material is doing.

    My first car had an 81 horsepower engine (at the wheels). I wonder if you can move enough heat energy with this stuff to power a small car?

    Alternatively, last week my Saturn blew up because of a sensor fault in the radiator. I cracked a head, torched a few hoses and quite a few other parts got messed up. The repair was close to $2000 to get it back on the road (I only owe $2600 on it). I wonder if this material could be used to cool an engine. What if you were to coat the engine block with this stuff? Could you just run an electric fan across the engine when it got too warm? That would save coolant, a radiator, hoses, a water pump etc! Maybe Porsche could make a smoking air cooled engine again. Maybe the classic Beetle would make a revival!
  • This just gives Kyle [hardocp.com] more reasons to burn out CPUs pushing them too damned far. The poor little dears, stressed to death trying to find the limits of cooling methodolgies...
  • I'm going to make underwear out of it to generate electricity for laptops. I'll call them ass-transformers. Or perhaps tighty-lighties. : )
  • Let me see here.

    A new Heat Sink material.

    Can also be used for generating power.

    Does this mean I can soon bring down my electrical bills by over-clocking my Pentium4 and adding an outlet to my computer case?

    Cool!

    I could stir fry my lunch in my cube!

    Goran

  • Correcting some misunderstandings (Score:1, Informative)

    by Anonymous Coward
    1) A lot of people have posted that this material is 2.4X as efficient as existing materials. This is not correct. According to the paper, they have achieved a 'Figure of Merit' (which is calculated in some fairly complex way) 2.4x greater than previous state of the art. Since they also note that there is no absolute theoretical limit to this metric, I think we can assume that it not only is not efficiency, it doesn't map to efficiency in any linear way.
    2) No one seems to have commented yet on the extraordinary thinness of these devices. They achieved a 70K thermal gradient across a 5 micron thickness when running in power conversion mode; this corresponds as they state to 134,000K per cm (!). It's also the root of their extremely fast thermal response (20,000 times faster than previous SoA). And it helps explain their very high watts-per-cm2 figures... in fact I'd say the microthickness, rather than the 2.4x 'efficiency' gain, is the real story here.
  • A good (and silent) solution for this would be to use this material to transfer the heat from a hot component to some circulating water in a condenser type setup. There could be an external container of recycled water that could be replaced when it gets too hot. This could even be automatic, with an electric valve and thermometer. This material could efficiently move the heat from the component to the water, which has a very high heat capacity, so the external container wouldn't have to be flushed very often. This might be a viable cooling method as processors and other components run at rapidly increasing temperatures.
  • Does this mean that if I were to hitch up one of my uncle's clydesdales to my PC, it could provide about 700 watts of cooling power? Neat!
  • As far as I know, there has never been a problem with current technology limiting the cooling your overclocked hardware (current generation thermoelectric coolers take care of that just fine), but rather has been the problem of preventing all the resulting condensation from ruining your expensive hardware.

    Also, you still have to deal with the problem of what to do with all that waste heat that is ultimately being produced by your processor and other hardware. Remember, these thermoelectric coolers aren't getting rid of the heat, they are just moving it to a different spot. I, for one, am more concerned about the ventilation present on my case than with just keeping the processor cool, as I've noticed a difference by as much as 10 degrees F hotter on the processor when I have the case open, which negates the ducting effect.

    Finally, as any experienced overclocker (me included) will tell you, no matter how much cooling you have for a chip, you will only be able to clock it so high before it becomes unbootable. Having a more efficient Peltier will not help you one bit in overclocking.

    So, sure, this is a cool discovery for materials physics, but it really isn't going to help people in the way you suggested in your post.

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