Controlling Window Opacity With A Switch

I have seen companies advertising this sort of switchable privacy glass, but I had never seen it in the wild.  Had this glass in my hotel this weekend.  Really cool.  If they can perfect glass that goes full dark or opaque with a switch, I have a ton of windows I would like to replace (sorry for the small image, playing with Google's new Motion Stills app to make gif's, but it does not seem to have a save to disk function so I had to text it to myself and this was all the resolution I got).


  1. ErikTheRed:

    On a scale of one to awesome, this is awesome.

  2. Brad Warbiany:

    That is cool. I think I came across it at a customer site once, where the conference room windows had this ability.

    Completely agree that if it actually could go full dark, *especially* if it had multiple settings for full dark, translucent, and transparent, it would be great in a house.

  3. bloke in france:

    Expect the Union of Curtain Makers and Concerned Scientists for Buggywhips to lobby to ban it.

  4. McG:

    That would actually be a good place for a dimmer switch, as opposed to two of the ceiling fans in my house, which have no light fixtures for the dimmers to control.

  5. What the...:

    Agree on the coolness of it. I'm a little surprised to see it making widespread use (i.e. throughout a hotel) since it seemed pricey last time I looked. When I was looking it was at films to retrofit by overlaying on existing windows and the natural state of the film was opaque and applying a current is what made it transparent. Going to make the greenies lose their mind - all windows needing to be supplied with a few mA of power each, all day, to maintain transparency. Think of the carbon!! (... and the children)

    Anyway, Boeing is has something similar incorporated in the windows of their 787 where they use a gel instead of a film.

  6. irandom419:

    That's why you need transparent solar cells on the outside. :-)

  7. What the...:

    For the good of the taxpayer, don't tell Elon.

  8. ErikTheRed:

    On the other hand, muh candlemakers are excited about this...

  9. Chuck:

    As someone who prefers the privacy of blinds, curtains, etc., I like that the power outage default is opaque. If I had these installed in my home, the last thing I would want is for a power outage to put my living room on display for the neighborhood.

  10. Brad Warbiany:

    That does highlight a potential wart... The default to be translucent would be nice. If the default was truly opaque, however, as soon as the power goes out your house would go black -- even in the middle of the day. If the default power-off behavior was merely translucent, however, at least it would let light through.

  11. Thomas Jackson:

    I flew to London last month on a plane with this type of window; these did go full dark. I believe the plane was a Boeing 787-9.

  12. randian:

    Electrochromic glass would be cool (literally) in cars. Default transparent (obvious safety problems with default opaque) but use a bit of juice to make them totally opaque when you park. Killer in hot climates like Coyote's.

  13. Sam P:

    These are basically huge arrays of liquid crystals in parallel instead of individually controllable as they would be in an LCD display. They ought to have variable opacity just by varying the voltage, though they probably don't have a linear voltage-opacity relationship (and your eyes don't have a linear relationship between light intensity and perceived brightness anyway).

    There is a variety of kinds of liquid crystals. If you only cared about transparent and opaque, there are liquid crystals which are bistable, you need power to put them into one state or the other but no power to maintain the state, which would seem to be a desirable choice for some of these window applications.

  14. marque2:

    Was refrigerator shopping last weekend. Several models have something like this so you can see inside the fridge without opening the door. Double tap on the front of the fridge and amazingly you can see your half empty milk and moldy cheese! Ah technology.