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Wriggling Heat Sinks 195

YourHero writes "Purdue researchers have come up with a new way to cool chips, in about 2 years. Just build a bunch of little piezoelectric fans (the waving kind, not the spinning kind). Since they don't spin, no bearings, less self-generated heat. Since they don't have magnets, no electromagnetic noise problems. And, of course, super-efficient. A press release and abstract for your reading pleasure. Formal presentation at THERMES 2002 Jan 15th."
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Wriggling Heat Sinks

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  • This is great! The best thing is the opportunity for ultra-quiet CPU and power supply fans for the pc. This means the drive is the last noisy component! It's good to be a geek.
    • Once me move to solid state storage, a la Holograms or some kind of RAM card, we'll only have noise coming from our optical drives.
    • Re:Quiet (Score:1, Insightful)

      by Anonymous Coward
      Power supply fan? Floppy drives? CD-ROM/DVD/Burner drives? Monitor? (They make noise) Printer? Keyboard? Mouse? (Unless you have a cool cordless optical one like mine.) And even then, your soundcard will still make noise. Even when you don't want it to, there is background hiss if you amplify a muted soundcard noise too much.
    • The article refers to low *electromagnetic* noise. It also points out that these piezo fans will require conventional fans to dissipate heat further away. Their action will lead to increased heat transfer at the chip itself.

      So, if I understand the article correctly, they won't in themselves lead to any reduction in audible noise.

      Oh well!
    • Since when are these things so quiet? When living in Korea in '86 (where air conditioning was rare, costly, and inefficient), I installed one in a MacPlus many years back and found it so annoying that I took it out as soon as I got back to the States. Of course, the MacPlus had no fan to begin with so any noise was a lot.
    • Well, the article clearly states:

      The innovative fans will not replace conventional fans. Instead, they will be used to enhance the cooling now provided by conventional fans and passive design features, such as heat-dissipating fins.

      So, unfortunately... not much quieter.
  • bye bye (Score:2, Funny)

    by MrGHemp ( 189288 )
    sounds like you'd just be waving the heat bye bye
  • by EvilBuu ( 145749 )
    "The concentrated circuits in a semiconductor computer chip can generate more heat per square centimeter of chip area than an area of equal size on the sun's surface."

    Is this true? If so I have so much more respect for my heatsink....
    • Well, the Sun's putting out about 1.4 kW/m^2 at the Earth's radius (around 160e9 meters), and the Sun's radius is around 1.4e9 meters, so the Sun's output at it's surface should be about 1.4 * (160/1.4)^2 = 18300 kW/m^2 = 1830 W/cm^2.

      I found a cool .pdf [intel.com] with the Watts/cm^2 values (on page 8; thanks, Google!) for Intel's CPUs up to the PIII, and apparantly the PIII's only at 40 W/cm^2. It's got all sorts of neat past milestones (hot plate) and future goals (nuclear reactor, rocket nozzle, even the Sun's surface, at about where my math claimed) to strive for.
      • While this is correct, there is a mystery as to why the surface of the sun is relatively cold compared to the other regions below and above it. Current theory is that it is due to the magnetic swirl that occurs near the surface, which gives the Sun a granular appearance. The power output figure you calcuated assumes a point source.
    • Trick questions (Score:5, Interesting)

      by freeweed ( 309734 ) on Friday December 14, 2001 @01:24AM (#2703037)
      Or rather, answers in this case. You commonly hear things like 'this is hotter than the surface of the SUN!!!' like it's some huge temperature. In reality, what is considered the 'surface' of the sun is only a few thousand degress (still pretty hot, but not THAT hot). It's the extreme lower depths, and especially the upper 'atmosphere' of the sun that is hot - in the range of millions of degrees.

    • Not True! The Pentium 4 generates about 25W/cm^2 while the sun generates about an order of magnitude more powere per unit area (634W/cm^2). This is assuming that my calculations are correct.
      • ahem...

        first: AMD chips run hotter than intel.

        second: what about certain milspec resistors? I'm not even going to mention high-power microlasers that are shipped with built-in peltiers...
    • The surface of the sun isn't "generating" any heat. That would be the core of the sun.

      So, yes, the statement holds...
  • by Anonymous Coward
    the fact that there are no magnets has nothing to do with the electromagnetic noise..
  • The innovative fans will not replace conventional fans. Instead, they will be used to enhance the cooling now provided by conventional fans and passive design features, such as heat-dissipating fins.

    Oops. Looks like the editor didn't read the article....

    Does this surprise anyone?
    • The only way I wont be surprised is if we dont see a repost of this tomorrow
  • It would be nice if they made it self-cleaning too. Those things accumulate a lot of dust. I use my dad's 5.0HP shop vac to clean the ones I have. It makes a loud ZZZZZZZZ and sucks the dust right out of there! Sounds like that would break one of these. Neat idea though. :D
  • by spacefem ( 443435 ) on Friday December 14, 2001 @12:39AM (#2702938) Homepage
    Doesn't anybody think it's cool to be noisy anymore? I mean, say what you will about being distracting and all that, but I'd love to impress my friends with a PC that sounds like a lawnmower. it's POWER! it's TOUGH! it's AMERICAN!

    sometimes worrying about things like noise is too girly, even for me.
    • There are countries that put much more emphasis than we do on the noise level of their computers. Japan especially is sensitive to the noise their systems make.

      Other than that, though, they're more efficient. Isn't that reason enough?
    • Re:awe come on... (Score:2, Interesting)

      by EvilBuu ( 145749 )
      Well, you can still have your 65dB Swiftech heatsink/fan, and your multitude of 80mm case fans and maybe a water pump for your overclocked GeForce3, but imagine if they put these on the fins of that heatsink. Not only would the surface area of the sink double or triple or more, but the heatsink would actively cool itself. That would bring your cpu die temp down another few degrees for sure, with barely any more sound, or power.
    • If it's too loud, you're too old!!!!

      Sorry, I couldn't resist :)
    • that is until 2 years later when the computer is obsolite. Then it's not only obsolite, it's damn noisy too! There's a dell powerEdge in my office running as a server, and the thing is loud as HELL. I'd just love to chuck the thing out the window and watch that huge fan in back kiss the pavement. Dell just wasn't thinking, I mean the thing has a 900Mhz processor and one hard drive. Beside it sits a PowerEdge 4400 with 3 15k RPM hard drives, dual 1Ghz processors, and a lot more components inside, and it doesn't even make half the noise. A lot of times it seems like computers are noisey when they don't have to be, which is why I'll never again buy a fan from Radioshack (yeah yeah, I was too lazy to look elsewhere). Having a suped up car with loud pipes is one thing, but a loud computer is sort of like trying to be manly by bragging about your toaster :)
    • Yes, but very noisy systems tend to get very distracting after a few hours.

      Ever listen to a 10,000 rpm or faster SCSI or Fibre Channel interface drive? Those things sound like jet engines ready to take off. It's small wonder why most higher-end ATA-100/133 hard drives out there are still running 7,200 rpm.

      Anyway, today's fan designs are way quieter than the past, thanks to quieter bearing design and careful design of the fan blades to reduce noise.
  • by Harumuka ( 219713 ) on Friday December 14, 2001 @12:41AM (#2702944)
    At least from Piezo Systems Inc. [piezo.com] in Cambridge, MA. Their specs are worth reproducing:
    • Input Voltage: 115VAC, 60 Hz
    • Capacitance: 15 nF
    • Power Consumption: 30 mW
    • Volume Flow Rate: 2 CFM, (0.9 l/s)
    • Peak Air Velocity: 400 FPM, (2.0 m/s)
    • Weight: 2.8 grams
    • Mounting: #2-56 clr. holes, 2 places
    • Temperature Range: -20 C to 70 C
    • EMI/RFI: None

    However, they're not cheap. Pricing starts at $149. Additionally there is a Piezoelectric Resonant Blade Element [piezo.com]. Interesting stuff. Hopefully mass production of piezoelectric fans will lower their price to the average customer range.

    • by Anonymous Coward
      Ouch. But, considering that you'd need 20 or so of those to replace a single conventional fan in flow rate, you'd be able to get their bulk prices. Then, they're only $49 each (or roughly $1000 per conventional fan).
      • Ouch. But, considering that you'd need 20 or so of those to replace a single conventional fan in flow rate, you'd be able to get their bulk prices.
        Not a bad estimate. Considering computer fans typically move 20-30 CFM, although high-end [coolerguys.com] fans which blow more than 50 CFM), you would need 10 to 15 piezoelectric fans to achieve equivalent volume air flow. In 5-24 quantites they cost $79, so that translates to $790 to $1185.

        Of course, laptop manufacturers could buy in bulk (100+) easily at $39. $390 to $585 per fan, significantly less.

        Yet, according to the article these are novelty fans. If it costs manufacturers $149 per novelty fan, I wonder what the "real" thing costs...

        • you would need 10 to 15 piezoelectric fans to achieve equivalent volume air flow...

          Of course, laptop manufacturers could buy in bulk (100+) easily at $39. $390 to $585 per fan, significantly less.

          Just how big is your laptop?

        • Of course a mere $500 to $600 bucks for a fan that does exactly what my current 50 dollar one does. sorry but the noise and other issues just don't cause enough of a headach to make me go and spend that much. hell thats as much or more than my WHOLE SYSTEM costs. damn! if my processor takes a dump because i have it undercooled than i'll spend the 200 bucks to buy a new one plus a better heatsink/fan combo.

          not worth it even for the "coolness factor"
  • by Henry V .009 ( 518000 ) on Friday December 14, 2001 @12:45AM (#2702953) Journal

    This is just an excuse for designers to make CPU's less efficent and more power hungry.


    Washington Post: Dec 13, 2018. Details are now emerging about the accident that irradiated much of Germany on Tuesday. Nothing is as yet confirmed, however, initial reports indicate that a heatsink was somehow removed from an AMD processor (PR rating 10,000,000). A bizzare terrorist group with the initials THG may have been involved. Containment was lost, and critical mass was reached almost immediately. AMD representatives have issued a statement in the wake of the carnage: "Obviously, they were using an improperly designed motherboard."

  • Piezo fans? Old hat. (Score:4, Informative)

    by FFFish ( 7567 ) on Friday December 14, 2001 @12:48AM (#2702957) Homepage
    Here's a picture of an old-style piezo fan [piezo.com]

    You used to be able to buy piezo fans for the old Mac Classic [acornworld.net] (read the list near the bottom of the page).

    IOW, piezo fans have been around since the mid-to-late 80's. Now, yes, I'll admit that they weren't very efficient (as in, they didn't move a lot of air)... but the concept has been there for eons.
  • Cooler (Score:3, Insightful)

    by Random Feature ( 84958 ) on Friday December 14, 2001 @12:51AM (#2702970) Homepage
    I don't mind the noise, but dissipating heat in general would be a good thing.

    The thing they need to do is make chips that run cooler. And yeah, Crusoe's do run cooler but they don't perform optimally in a task-switching environment.

    Cooling the CPU is fine, but the heat has to go somewhere and a better solution is to go back to the drawing board and figure out how to reduce the heat output in the first place. PLEASE.
    • How about harnessing that heat somehow. It seems to me that the problem isn't the heat, it's the energy waste. Like maybe hook your water-cooling setup into your water heater or something.

      Although I do generally tend to sneer at "green" houses that basically just do that.

      Now that I think about it, there was a project to turn your pc into a still, but the link http://exaflop.org/docs/x86still/ doesn't seem to work.
    • The physics are quite simple. For any non-superconducting material, when you run electricity through the material, you generate heat. To make processors faster, Intel (et al) must pack the transistors tighter and tighter (avoiding transmission latency). The more you pack these little heat producing components, the more heat they generate per square centimeter. We have long since passed the point where the cpu's could self dissipate heat. "Going back to drawing boards" may seem like a trivial idea, but trust me, a lot of bright boys have been back at those drawing boards for quite a long time!
  • by BigBir3d ( 454486 ) on Friday December 14, 2001 @12:52AM (#2702971) Journal
    What are the chances of the conventional ball bearing fans, in the very computers that are doing all the mathematical modeling, will go on strike??

    Self-preservation is quite a motivator.
  • Nothing New (Score:2, Informative)

    by pcjunky ( 517872 )
    I have had one of these fans cooling my sterio for years. I got mine as a sample while working for a crystal manufacurer in 1984. It makes VERY little noise but does not even begin to move enough air to cool a modern CPU. These new ones would have to be 10 times more powerful.
  • Air Flow (Score:2, Insightful)

    by ruvreve ( 216004 )
    I didn't see any specs as to the rate of air flow these things can produce. Assuming they are optimized given the 'provided' mathematical models. Any chance these models are as easy to understand as the instructions they put on coke cans?

    The article stated that these fans could have blades up to an inch long, anybody have any opinions on whether this could replace the large fans in cars that are used for air flow over the engine and radiator? This would make working on your car while it is still running a little bit safer. But of course the saying "Make something idiot proof and somebody will make a better idiot."

    And since the topic of energy consumption was brought up, how about using these instead of ceiling fans in our homes. Being that I have never seen one of these in action I bet you could make them look aestically attractive at least to us nerds. Sort of like having a huge rack of all black stereo equipment.
  • 2 years? (Score:4, Funny)

    by minusthink ( 218231 ) on Friday December 14, 2001 @01:08AM (#2703003)
    Purdue researchers have come up with a new way to cool chips, in about 2 years.

    I don't know what kind of chips these researchers are using, but the kind I use build up heat a lot faster, and thus need to be cooled constantly, not just every two years.

    lame jokes brought to you by:

  • by Jucius Maximus ( 229128 ) <m4encxb2swNO@SPAMsnkmail.com> on Friday December 14, 2001 @01:15AM (#2703015) Journal
    For those who are unaware, piezoelectric crystals are items that will change shape under the application of an electric field and/or generate a potential difference (i.e. a voltage) when squeezed.

    They're used in inkjet printers - they're in ink some cartridge when an electric field is applied to them and they change shape, forcing the ink out of the I also hear the they used them in the ipod for some sort of playlist control mechanism.

  • I'd much rather trust my components to one large, well made fan with some intelligent ducting inside the case to deliver the air flow where its needed. I think this is one area where some of the big system manufacturers still have a big advantage over a typical 'roll your own' case. Small cooling devices are just too fragile and unreliable, and multiple points of failure are unacceptable, especially in server applications IMHO.
    • You have no idea (Score:1, Insightful)

      by Anonymous Coward

      I just love it how these 13 year olds spout off shit to try and increase their karma.

      I'd much rather trust my components to one large, well made fan... and multiple points of failure are unacceptable, especially in server applications IMHO.

      Every fucking server that I have worked on has at least 5 good quality fans. The compaq prolients that I'm working on now (quad Xeon's) has 2 power supply fans, two CPU fans, two fans over the PCI slots and an extra ventalation fan. All hot-swappable, all redundent.

      I don't give a fuck how large your fan is, if it fails, you are fucked.

      This is why real servers have multiple fans (even if it means muntiple points of failure)

      • Gosh dude! Take a Prozac. Sounds like you are having a rough day. I was actually thinking of the HP Netserver E40's we run Novell on and how much better I feel about them than I do about the built-from-local-parts Athlon system I built to replace a failed Exchange server. I keep seeing it going up in smoke in my dreams like the first one did when the CPU fan failed. I have yet to have one of the main fans fail on one of the HP's. Even the older Netserver 6/66's that I have converted to Linux after they were retired have never seen a failed main fan. Not all servers are huge multi-processor beasts with redundant systems. Sorry, haven't been 13 in many years... Try to get some rest. Drink a beer.
      • I really agree with your assessments.

        Anyway, if the case is relatively open inside, all you need is a power supply with really decent venting (like the Enermax 300W unit with its double fans I'm using right now), a decent CPU cooler and a expansion slot fan to vent the hot air out of the lower portion of the system case. I've never had any heat-related failures.
    • Great, a single point of failure sounds SO much better that having redundant fans....
    • Multiple points of failure in a system without cycles, such as A->B->C->D->E are bad. If you're going from A->E, B, C, or D could fail and ruin the whole thing. However, if you had A->B & A->C & A->D, etc... then more points of failure are a Good Thing. Now look at another case. If you have a device A that does 100% of the work, and it fails, than you have 100% failure. If you have devices A, B, C, and D, each doing 25% of the work, and one fails, you only have 25% failure. More points of failure is good in this case. With a ton of these tiny fans, if some fail, the system continues to work without damage. Think, write, read, think, rewrite, think, preview, post. Try it.
    • Where I come from "single point of failure" = "bad." The idea is to have complementary elements which can pick up the slack should something go wrong. On a WAN, that means multiple access points to the Internet for failover. With storage, it means RAID. In a case, it means multiple fans.
  • by xeno ( 2667 ) on Friday December 14, 2001 @01:44AM (#2703077)
    Ok, I just got this be-yoo-t-ful image in my mind:

    Imagine the piezoelectric fan on a larger scale, not just waving a metal+ceramic blade (single flexible surface area), but creating an undulating sheet about the size of a letter/a4 size piece of paper using stripes of piezoelectric flexion areas that create a wave every 2-3cm. Now combine this with the latest in flexible printed circuitry top and bottom (or 2 layers top and bottom, for the really adventurous). I'd imagine you might also need periodic non-flexible stripes (ends?) for components and connects that can't be made flexible. Then add a lower-power processor and put it into an enclosure only slightly larger than the wave height, such as, say, a laptop computer housing. What do you have?

    You'd get a motherboard that cools itself by cilia-like swimming/undulation movement that pushes air (against the enclosure) across its surface silently.

    You'd get quieter rackmount systems, with 1U or "blade" servers that self-vent. ("Ah, yah need tah balance yer server there, buddy, the blades are outta sync.")

    You get a laptop that you might enjoy putting in your lap. (On second thought, I'm not sure I want to sit next to someone on a plane with a two-stroke laptop...)

    just my $0.02
    -Jon Espenschied
  • by Anonymous Coward
    Back in the 80s, you could get piezo fans for the Mac Plus' or you could build your own Mac Chimney. It was basically a pyramid that sat on top of the Mac with a 2" square chimney stack that extended from the top of the pyramid for a height of about 18". Supposedly, it provided the necessary draft to pull the heat out of the Mac Plus. For some reason my wife never appreciated the beauty of it sitting ontop of her computer...

    I see no reason why the same technology could not be applied to modern CPUs and computers. It would be energy efficient to say the least..

    On a side note, if you want an interesting geometry problem, try to mathematically design a pyramid out of cardboard for a specific height and base.

  • Fans, fans fans. Might as well use a Tesla Turbine [execpc.com] to move ungodly volumes of air with very little noise. No fan blades, no resonance with the heat sink blades to make loud whine or buzz. Just the hiss of moving air over the heat sink blades.

    However, solid state heat transfer has been around for ages. I would love to find an advert for a 12-volt refridgerator for camping that I saw back in the 1970's. It used a pezo film between two heat sinks, one on the inside and one on the outside. Apply the voltage, and heat was moved actively into the outside heat sink, enough to chill your beer and keep the fish fresh on the trip home.

    Put such a film between the chip and a heat sink. Gosh wow, a cool CPU.


    • I actually used to have a bag of these things, small ones that were designed to stick on to high powered DIP chips with thermal epoxy. Peltier Junctions is the proper name. I tried to sell some of them to a surplus dealer when I moved and had to clean out the workshop but they wouldn't take them because they were classified as hazardous waste! Seems that they used to use Beryllium in the manufacturing process, so I was told, and they were very toxic if they got chipped.
    • Um dude,
      It's called a peltier and people do use them to cool CPUs. Although they acutlly just pump the heat from one side to another so it doesn't really help that much.
  • This might be helpful for wearables -- and the article authors seem to think so too:

    From the article:

    Piezoelectric fans are very low power, small, very low noise, solid-state devices that have recently emerged as viable thermal management solutions for a variety of portable electronics applications including laptop computers, cellular phones and wearable computers.

  • These seem pretty cool (no pun intended) but what happens when it's time to replace your CPU. Just reach in and grab the ol micro-fan heatsink and *crunch* tiny flakes of fan blades all over the inside of your case.
    I think I'll just stick with my technique of periodically spraying water into my case.
  • They say you can use a surface of these fans each of which is only a hair's-width long to cool chips. Do they have any concept of the idea of dust?? Every six months or so I have to take one of those cans to my fans to remove the huge air blocking clumps that seem to clog up the entire fan. Are we gonna have to start purchasing a special cleaner that we have to dip these into every couple of weeks? My monitors have a pretty much permanent grey film that doesn't wash away on them from a year or two of the Los Angeles smog. I'd hate to see what particles that small will do to the effectiveness of these fans.
  • Seriously. How many new ways do we have to think up to cool down processors that are too hot to begin with? Why not fix the processor so it doesn't run so hot? Come to think of it, it's already been done by Apple/IBM/Motorola. It's called the PowerPC.

    I'm not trolling here, folks. Is all this effort worth it? Why not just make the jump to a better architecture that runs 80% cooler? With all the effort that's gone into cooling technologies, we'd probably have a 2.5 GHz G5 by now. If you think it's impossible to make a radical jump of chipset, let me remind you of Apple (68k PPC), Be (PPC x86), WinNT (x86 PPC).

    I avoid Windows because I think it's bad software. I use MacOS or Linux instead. I avoid Intel because I think it's bad hardware. I use PowerPC (AMD if I really need an x86 solution) instead. I think of it as promoting positive change in the industry.

    • What effort? Did the CPU manufacturers ask the researchers to come up with something new? Those researchers found an opportunity and are pursuing it.

      With all the effor to keep floor clean, wouldn't you think they'd find a way to stop all that dust from hitting the ground rather than developing new vacuums or brooms? That problem has been around for centuries.

      With all that effort to keep shoes on, wouldn't you think they'd develop something other than strings to keep them on? Think how much energy is wasted tying shoes every day! And then you have to do it several times for some shoes!

      On a less flippant note, the people who design processors are engineers. They're professionals. Do you think they're lazy? Stupid? Ignorant? What do you think it is that makes them avoid the heat issue? I tend to think it's a difficult problem, and that there are other problems that are more important. If they could fix it simply they would. If it were of paramount importance they would get rid of the heat.

      When heat is the problem keeping them from making a product that is useful and marketable they'll change it. Until then they focus on other things, and they make you buy a heat managment accessory.

      What's so hard to understand about that?
  • Am I the only one who doesn't get the idea here?
    $149 for a peizoelectric fan... how is this going to work better than a 1800's style fan? I can't see how such a thing would work at all, unless you had stacked peltiers.
  • Purdue researchers have come up with a new way to cool chips, in about 2 years . . . Since they don't have magnets, no electromagnetic noise problems. And, of course, super-efficient.

    How super-efficient can it be if it takes two years to cool the chip?
  • aren't claiming its anything new.

    When I did brain surgery on my ancient Mac to slap in an extra meg and a half and a SCSI interface I had to install the 'flapper' fan or whatch my case do a Dali "soft watch."

    Gluing a piezo fan onto the chip is not very smart anyway. And it does generate some 'flexing' heat where there is the least air motion. And it makes noise like a butterfly on speed.

    You don't get something for nothing. Moving air other than by convection causes turbulence which causes vibrations. Vibration IS noise. Which is more irritating, a flapping buzz or a whirling whoosh? Its a matter of taste.
  • Mr Hat: Boy that Ricki Ingles sure can wiggle his hot ass!
    Student: Pay attention Mr Hat... WHAT DID YOU JUST SAY?

    And the rest is history.

  • Hey baby, why don't you follow me downstairs to the computer room. I've got a wriggling heat sink that you need to check out.
  • I can't agree with the no E-M interference statement. I can see there being less of it, but piezoelectric materials run on the concept of using a voltage differential to change the shape of the material. So you have to use electric current to produce the waving motion. I guess if the difference in EM fields is in orders of magnitude, than you can assume there is virtually no EM interference.
  • We used piezoelectric crystals in a Genomics Lab at the University of Wisconsin and there are two problems that immediately come to mind at the mention of this application (and an afterthought).

    For one, they are very costly. Perhaps with their proliferation, the costs would go down, perhaps not.

    Second, piezoelectric crystals are very fragile. They have a tendency to crumble when too much force is applied to them. Unless this problem has been solved, transport of such a device could easily cause damage. See point #1.

    Afterthought, there may also be a problem with condensation associated with the use of piezoelectrics. Without the air flow of a fan, devices of this sort are subject to water vapor condensation, which, as everybody knows, is a bad thing to have happening on your mother board. In an analogous situation, my brother and I tried using Peltier junctions to cool our hot rod, and the result was a watery mess. (Coincidentally, I now work for an unnamed company that relies on Peltier junctions for rapid thermal cycling, and to solve the condensation problem, we have relied on, you've got it, heat sinks and fans).
  • This little piezo fan may be efficient, but anyone who says it doesn't radiate electromagnetic energy is clearly showing his own ignorance.

    There has got to be something less than perfect efficiency and whatever little inefficiency it might be, it almost certainly has to contain some electromagnetic radiation. It may well be much less, perhaps even orders of magnitude less, EM radiation. But you can be certain that it exists.

    Oh, and by the way, peizo effect movements are not new. I seem to remember ads for them in Digi-Key catalogs years ago. I seem to remember that they were quite pricey too.

    You want a flutter in your lap -top? Get a feather. :-)
  • which is a Good Thing(tm).

    With 5 boxen in the corner of the Dining Room, I'm under significant pressure from the SO to keep the sound pressure levels down.

    "Battle (that's really my name), It looks like the bridge of the Star Trek in there!!"
  • If these fans really use 1/150 the electricity of a conventional fan, there should be an effort to scale them up to the size used to cool people.

    It would be cool to have one of these sitting om my desk, flapping at me, while drawing very little power.

Never buy what you do not want because it is cheap; it will be dear to you. -- Thomas Jefferson