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Using Aluminum Oxide Paint To Secure Wi-Fi

Posted by Soulskill on from the prank-possibilities-abound dept.

eldavojohn writes "The BBC reports on people using aluminum oxide in their paint to block Wi-Fi signals from leaving their home or business. Aluminum oxide resonates at the same frequency as Wi-Fi signals and other radio waves, blocking data from going outside a building. It's not a flawless solution, as it may also block AM/FM signals. You or your neighbors may be unwittingly using this already, as most pre-finished wood flooring uses aluminum oxide as a protective coating."

4 of 271 comments (clear)

  1. Note: AlFeO *not* Al2O3 by Anonymous Coward · · Score: 5, Informative

    Note, the material concerned is Aluminium IRON oxide. Big difference. Aluminium oxide is a good dielectric and would be bugger all use for RF shielding. Oh and the article is a wierd too: it talks about 100GHz shielding where WiFi bands are ~ 2.5GHz.

  2. Re:Resonance at other frequencies? by John+Hasler · · Score: 5, Informative

    > What frequencies are not resonant in Aouminum Oxide paint?

    The reporter is just yammering. He hasn't the foggiest idea what the word "resonant" means and knows less than nothing about radio. All we can glean from this is that someone has put out a press release about rf absorbant paint, something that has been around for decades.

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  3. Re:Cellphone reception? by morgan_greywolf · · Score: 5, Informative

    Try reading more carefully:

    FTFA:

    While paints blocking lower frequencies have been available for some time, Mr Ohkoshi's technology is the first to absorb frequencies transmitting at 100GHz (gigahertz). Signals carrying a larger amount of data - such as wireless internet - travel at a higher frequency than, for example, FM radio.

    ...

    "Our current mobile phones work at much lower frequencies, around 1.5 gigahertz. But, our material can also absorb frequencies that low, so you could block phone signals from outside and stop people's phones ringing during the movie," he said.

    From the sounds of it, just about anything below 100 GHz gets blocked. That means cellphones, too.

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  4. Re:Resonance at other frequencies? by Anonymous Coward · · Score: 5, Informative

    All we can glean from this is that someone has put out a press release about rf absorbant paint, something that has been around for decades.

    Using information in the article I was able to find the actual science paper. It turns out they are able to tune the resonate frequency of this paint. Very cool. However, the it doesn't go all the way down to 2.4 GHz. That's a pretty long wavelength for this process.