Self Frosting glass

I remember hearing about this glass / polymer which would be clear and when given a current or some sort of outside influence it would turn to a frosted view. Anyone know where a “How Stuff Works”-ish article is on this stuff? It just seems too cool!

I think the stuff you’re referring to is a liquid-crystal glass window. It is normally forsted - usually a light gray. But if an electric current is applied to the liquid crystals, they come into alignment and poof - instant clear glass. Cut off the current and the glass quickly (but not instantly) fades to the frosted gray. Cool stuff. I think I saw it in the conference room in the movie “Philadelphia”, but I could be remembering the wrong film.

Edmund Scientific used to sell small panes of the stuff for educational purposes. Maybe I can find a link…

This company sells it under the trade name Priva Lite. It works by using liquid crystal technology, as explained on the linked page.

A student of mine a couple years ago got his father’s distribution company - for the glass - to donate some to our institution. After a brief demo one of the deans had it installed in her office/conference room. Cool stuff.

In Florida, there’s an ice cream place where the restroom walls are made of this stuff. If you forget to turn the door handle, everyone in the restroom can see you pee.

er… that should be “everyone in the restaurant”

I am struggling, flopping - beachwed-fish=like, straining, trying to understand why they would install it - is it terribly important that the customers eating their ice cream can view the urinal while it is vacant?


Please tell me this is a whoosh.

I’m not really sure. I think most people who watch it are secretly hoping, in their meanest heart of hearts, that the next person who uses it will forget to lock the door and publicly humiliate himself before the ice-cream-eating mob. It’s sort of the same impulse that keeps people tuning in to America’s Funniest Videos to see people getting hit in the crotch with heavy objects. There’s a link with pictures here.

I’m not sure that this is quite the same thing as LCD, though. LCDs work by polarization, with the liquid crystals themselves having a polarization that can be rotated, and covered by a fixed polarizer in some direction. Match the liquid crystals to the cover, and light can get through, or rotate them 90 degrees, and light is blocked. The problem here, though, is that you’re always looking through at least one polarizer, which means that you’re always losing at least half of the incoming light (assuming the light starts off unpolarized, a reasonable assumption for unreflected sunlight).

I don’t think it uses a fixed polarising filter; when the current is applied, the LCD polarises and lets light through (so I suppose you’re still looking through a polariser) - when the current is removed, it returns to a randomly polarised state - because of the thickness of the LCD emulsion, any given molecule will most likely be overlaid by another in different orientation, so light is scattered

I don’t think so. I saw a documentary on the “X <superlative modifer meaning coolest or something> bathrooms”.