toilets

after years of research, technology finally made it's way into the life of ordinary people in the form of..tada!! opaque restroom doors! hahahahahaha.

it was really funny because we went inside and told the waiter we are students from the university and we were told their restroom has a really interesting application of a certain technology we were studying and so we just asked to take a peek. he asked, and in what course is this? maybe to check we weren't just dropping by to use their restroom haha. so we said, yeah it's in optical materials and he was like yeah yeah i can see why you're interested. go ahead and take a look. :D

it's weird, yes, having transparent restroom doors haha. but, you see, when the lock is open (right side) the door is transparent and you can actually look into the stall. when you click the lock, the whole pane suddenly goes opaque!

the last time jake went there he was told it is some sort of gas and some chemical reaction happens when you click the lock. but it's actually not a gas, what actually happens is this: in between the glass plates is a thin film of polymer or plastic infused with (blobs of) liquid crystals. it's the liquid crystals (LC) we are interested in. an LC is a kind of material that has both liquid and crystalline properties in the sense that its molecules can move around freely (slide and glide over each other and stuff) but may be oriented in specific ways. now why is this? it's mainly due to the shape of the molecule itself which is elongated which is why it's usually drawn as cigar-like shapes in textbooks.

now, another interesting property of these LCs is that they tend to re-orient themselves when exposed to electric field. this is what creates the interesting effect we see above. you see, when no electric field is applied, the blobs of LC molecules don't align all in the same direction. some points upward, others to the side, and just basically when light comes in it is scattered in all directions. so the whole film of polymer/LC is practically anisotropic and the pane is transparent.

when you apply electric field, however, the LCs align themselves according to the field and you can tweak this property in such a way that you do not allow light to pass through. and so once you apply voltage, which is what happens when you click the lock, you now have an opaque pane! tadaaaa! and there you have it, liquid crystals at it's best haha :) and, you know, this happens instantaneously like there is practically no observable time difference between the time you click the lock and the time the pane becomes opaque. on a side note, the same class of materials are also being used in your phones or monitors or laptops (liquid crystal displays, LCD).

anyway, this one is in a restaurant called belga queen somewhere in graslei.

when you're in belgium, go visit this place :P
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