transparent glass doors changing into opaque

I was at a restaurant in New York where the doors to the bathroom were transparent but once you were inside and the door made contact with the lock, it immediately went opaque and the light turned on. i imagine this to be some sort of electrical conductive material embedded in the glass.
Does anyone know where I can find this technology, learn more about it or if it is possible to do the same with plastics?
Thanks!

Liquid crystal doors.
Watch CSI more often :sunglasses: they were ‘feaured’ in an episode of CSI miami.
For info, just google for liquid crystal doors and you should be set.

at the studio space where i work they have that type of glass, and its cool, at a flip of a switch it goes from c-thru to foggy/ frosted look. really cool. but expensive and I have been told not too stong. it deals with teh electricity running through the molecules in the glass and it triggers an reaction-dont know much about it.

expensive-

There’s a thin layer of liquid crystals embedded into the glass almost like an LCD monitor (without light source) when a current is applied the liquid crystals change polarity and the crystals line up perpendicular to the polarized glass (or polarized plastic film inside the glass) hance less light is able to pass through.

… or something like that.

Those doors are made by laminating an electrochromatic film between layers of glass. It is a liquid crystal film that changes from opaque to clear when current is applied to it.
For more information about this stuff I’d start at one of these sites:

http://www.sggprivalite.com/en/applicref/applic_fr.html

http://www.glassonweb.com/glassmanual/topics/index/crystal.htm

I tried to find out how I could buy just the film to experiment with, but haven’t found any place that sells it any form other than finished products.

Saint-Gobain make Priva-Lite, which is laminated glass comprising 2 sheets of glass, a liquid crystal film, and a further 2 plastic interlayers. the guy above explained the crystals reaction to a current. i have used priva-lite in many projects, and its good stuff…although its never actually “clear”. its kind of milky. you would never notice unless you put a piece of normal glass by it. i visited the factory in belgium where they make it, much to my displeasure. belgium industrial estates are perhaps the most depressing areas in europe.
my sources tell me that pilkington are developing a similar glass that can CHANGE COLOUR when the current is varied. thats gonna be fun.

Ok, super! Thanks for all the answers.
But now the question is:
Can I mold it into a shape such as a vase or tube?
I only see flat surfaces…
Thanks

for a curved surface you might try flexible organic LED though they also produce light not just change color (I’m also not sure that the flexible oled’s are transparent or that the transparent ones are flexible; seem to be two slightly different technologies) they use a plastic substrate (which is why they’re flexible) instead of glass which is the reason LCD’s are almost always flat (lcd has to be viewed through polarized glass to be visible)