Wriggling Heat Sinks

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."

Comments

electomagnetic noise....

[Anonymous Coward]

the fact that there are no magnets has nothing to do with the electromagnetic noise..

Still need Whirly-Birds

[miracle69]

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?

Piezoelectric fans are already available

[Harumuka]

At least from Piezo Systems Inc. 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. Interesting stuff. Hopefully mass production of piezoelectric fans will lower their price to the average customer range.

Re:Piezoelectric fans are already available

[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).

Re:Piezoelectric fans are already available

[Harumuka]

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 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...

Piezo fans? Old hat.

[FFFish]

Here's a picture of an old-style piezo fan

You used to be able to buy piezo fans for the old Mac Classic (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.

Nothing New

[pcjunky]

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.

Answer: what is piezoelectric?

[Jucius Maximus]

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.