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Bell Labs Plants Nanograss to Cool Mobile Chips

Posted by CowboyNeal on from the ever-so-careful-watering-of-electronics dept.

LoadWB writes "TechWeb has an article about Bell Labs' new liquid cooling technology for mobile processors. The tech, called 'nanograss' is described as 'tiny tubes that spray liquid on chip hot spots.' The use of this cooling technology reduces the power required to actively remove heat from mobile processors. Other applications are possible, but it seems it was primarily developed for use with mobile CPUs."

6 of 109 comments (clear)

  1. Where does the energy go? by Anonymous Coward · · Score: 5, Insightful

    You still have the problem of getting the energy from the cpu out of the computer, just because you move it from the chip to the liquid doesn't really help all that much in itself. You still have all the same old problems. Apparently they have managed to come up with something, but it doesn't really seem to be such a great innovation as it is being hyped up to be..

  2. Nano Nano by Anonymous Coward · · Score: 5, Funny

    In other news, John Deere has just released the "NanoMower".

    The NanoHippy add-on (for nanograss collection) is TBA. NanoNarc soon to follow. No word as to the cooling effects of either.

  3. Hmm. . . . by ookabooka · · Score: 5, Interesting

    Brings a whole new meaning to watering the grass. . .
    Seriously though, its nice to see some new heat dissipation technologies. . . but it still comes down to how much thermal energy the chip pumps out. . . this is merely equivalent to a more efficient fan/heatsink. Though it should keep the chips at a cooler temperature (compared to their standard air counterparts) your laptop is still gonna get way too hot to put on your lap.

    --
    If you are about to mod me down, keep in mind that this post was most likely sarcastic.
    1. Re:Hmm. . . . by moreati · · Score: 5, Interesting

      If it works, it will push the envolope, improving not just total power consumption, but weight, volume & temperature also.

      We already have water cooling at the macro level - a radiator + pump + heat exchanger + resevoir system will give a lower temp and less noise for the same or better heat removal capacity eg . these.

      The improvement this would provide is watercooling at the micro level, just to the most critical components. The improvement in heat conductivity from the chip to the cooler should mean lower temps for the same transfer. Cooler.

      The bore of the tubes implies 50 ml liquid, rather than upto 1 litre (2 pints) currently used. Lighter.

      Less water for the same heat transfer means a smaller pump. Lower resistance in the chip due to lower temps would mean less power disipation. Longer running on batteries.

      On the air side (dissipation from the cooler to the environment), heat exchanger tubing with ~100 micron diameter (the artivle soesn't say they've done this, but it seems a logical extension) gives enourmous surface area/unit volume, giving better dissipation for the same airflow. Quieter.

      So I would surmise this is ideal for laptops, it improves all 3 of the key features - weight, longevity and actually-able-to-use-it-on-my-lapiness.

  4. Wow by Un0r1g1nal · · Score: 5, Interesting

    This looks like really good stuff, being able to localise the temperature dissipation would be handy for lots of technologies. I hope that this one gets developed fully and hits the markets soon. The better the cooling capacity the more we can clock our chips :)

    As for having to refill the cooling agent periodically, I doubt that this would be a problem with mobile phones, this would be a completly self contained cooling system, much like a heatsink is today, (only a heatsink doesnt have a liquid running around the inside of it :P). The likelyhood is that by the time the liquid would need replacing - if ever, the phone would be at lesat a few years old, and so the owner would probably have it lying around in some drawer since they got their brand spanking new top of the range all singing all dancing holographic video phone...

    --
    If at first you DON'T succeed, Skydiving is NOT for YOU!!
  5. A word from technology inventor by nanograss · · Score: 5, Informative

    Guys, certainly a great pleasure to see so much interest in our technology.

    Unfortunately, the TechWeb article is not that accurate. In particular, the statement that "nanograss" consists of tiny tubes that can spray liquid on chip hot spots is totally off mark.

    What we call "nanograss" is a carpet of tiny nanocolumns (or nanoposts, but not tubes) each several hundred nanometers in diameter that cover the surface of say microchannel. The posts are treated with water repellant polymer coating and thus are not easy to wet. As the result the cooling liquid (such as water) can't penetrate inside this carpet and stays suspended on the tips of the nanoposts. Thus, flow of a liquid in a microchannel that has walls covered with the nanograss requires much less pressure head than in a regular channel. The liquid literally slides along the walls without touching them suspended by a tiny layer of air as in air hockey table.

    Now, the trick is that we can intentionally design the nanograss such, that it can hold the liquid suspended on nanoposts only at the temperatures below a certain predetermined threshold. If the temperature exceeds this threshold the liquid sags through the nanograss and gets into direct contact with the wall. Needless to say that in this case thermal transfer from the wall to the liquid is greatly enhanced; the thin layer of air that isolates the wall from the cooling liquid is now gone. Thus the microchannels with the coolant that are located above the hottest areas on the chip (so-called hot spots) will have coolant penetrating through the nanograss and thus provide much better cooling exactly where the hot spots are. The system is self-adjusting and would automatically adapt to any arrangement of the hot spots. The obvious applications are in CPU and GPU cooling, as well as in telecom power electronics.

    In addition to the application in cooling, there are multiple applications in other areas, ranging from electrical nano-batteries and biochem lab-on-a-chip devices to seagoing vessels. Indeed, wherever we have liquids we also have solid surfaces that contact them; thus you can think of a countless nanograss applications out there.

    For those of you who are interested in further details the link to the Bell Labs press release is

    http://www.newstream.com/cgi-bin/display_story.cgi ?12664

    Also, the work will be published in May, 11 issue of Langmuir.

    Best Regards, Tom Krupenkin