Another 'What is it?' game

curt0909 · Post by **curt0909** » Sat May 11, 2013 12:09 am

Its time for another game of 'What is it?'! Every hint I'm currently thinking of is a dead give away so I'll save them for now. All photos where taken of the same slide and specimen. Polarized, transmitted light, 20x objectives 0.4-0.46 NA

Pixel crop of above photo

Good luck

rjlittlefield · Post by **rjlittlefield** » Sat May 11, 2013 12:23 am

Hhmm... I'm thinking it's an optically active smear of something that beaded up slightly on the slide. Corn syrup?

--Rik

curt0909 · Post by **curt0909** » Sat May 11, 2013 12:28 am

Good start Rik. It is a smear of a liquid that beaded up on the slide. I only had a VERY small amount to work with so I spread it with my finger on the slide.

rjlittlefield · Post by **rjlittlefield** » Sat May 11, 2013 12:32 am

Aha! A clue: the material is not extremely toxic!

--Rik

curt0909 · Post by **curt0909** » Sat May 11, 2013 1:40 am

Not acutely toxic. I should have clarified, I did have gloves on. If it was to get on your skin it should be washed off with soap.

curt0909 · Post by **curt0909** » Sat May 11, 2013 5:06 pm

Hint: It is something you would need to view this post...

rjlittlefield · Post by **rjlittlefield** » Sat May 11, 2013 6:27 pm

curt0909 wrote:Every hint I'm currently thinking of is a dead give away so I'll save them for now.

I see your problem...

--Rik

curt0909 · Post by **curt0909** » Sat May 11, 2013 9:11 pm

rjlittlefield wrote: I see your problem...

Yes, its a real dilemma.

Jacek · Post by **Jacek** » Sun May 12, 2013 12:14 am

I do not know what it is, but it looks amazing

canonian · Post by **canonian** » Sun May 12, 2013 12:57 am

I'll start a wild guess:
some type of two component epoxy resin or glue?
(allthough I can not think of a way how it is needed to view this post)

Planapo · Post by **Planapo** » Sun May 12, 2013 1:27 am

Smear of a silicone oil?
(Then "to view this post" would refer to the Si component.)

--Betty

harisA · Post by **harisA** » Sun May 12, 2013 8:32 am

liquid crystal...

curt0909 · Post by **curt0909** » Sun May 12, 2013 11:11 am

harisA wrote:liquid crystal...

We have a winner!

Super interesting stuff. I had a broken portable dvd player with a 10" screen. I originally wanted to see if I could remove the polarizers intact but my gorilla-like finesse quickly broke them to pieces. So I set my eyes on the liquid crystal. There is such a small amount of liquid crystal that it exhibits thin film interference. I simply 'squeegeed' the liquid as best I could with my fingers(wearing latex gloves) and transferred it to the slide.

I had never seen a birefringent liquid before. I found I could change the birefringence by blowing on the larger beads of liquid. This was likely due to change in thickness of the material. I have several video clips of this. I'll try to put the video together later today.

I'm trying to source some raw material now and any help would be greatly appreciated. I've found very small amounts of single nematic liquid crystal chemicals from sigma aldrich. From my understanding the formulas used in lcd screens are combinations of several chemicals in a mixture. Alibaba has such a mixture but the lowest quantity available is 1kilo at $1700!

I'm hoping someone can point me in the right direction with this.

Same area as another photo but different angle of compensator

A crop of that image

Here is a crop from photo #2

rjlittlefield · Post by **rjlittlefield** » Sun May 12, 2013 11:25 am

It's conceivable you could also change the appearance by exposing the liquid to a strong magnetic field. (See http://en.wikipedia.org/wiki/Liquid_cry ... ld_effects.)

I can't get any of my liquid crystal displays to react to magnets, but I can only test them when they're turned on, and in that case their state should be dominated by the electric field.

With isolated liquid and polarized illumination, you might be able to get some effect like I got HERE using magnetic viewing film and colored lights.

--Rik

curt0909 · Post by **curt0909** » Sun May 12, 2013 12:08 pm

My original plan was to take a drop of liquid(which I wasn't able to obtain from the screen) and put it on the slide. Put 2 very fine copper wires at each end of the drop. Cover with coverslip. Seal with nail polish. I was dead in the water at step one. If I can get my hands on a decent amount of raw material I could try some interesting experiments with the stuff. I'm probably going to buy a gram from sigma to play with . At $50-70 a pop its kind of pricey though.

I didn't even think to use magnets. I never dared to put a magnet near my LCD screens. I know they really mess with the image from CRT screens. I'll give it a shot next time I have a slide of LC. I know a magnetic field can affect polarized light. If you direct linear polarized light between two attracting magnetic poles it will change the polarization to circular.

That magnetic film is amazing. The patterns are not what I expected to see. I'm going to order some as soon as I finish typing this.

I have another type of cholestric liquid crystal (from a color changing mouse pad

)I'll try to make a slide of later. Should be easy to change the temp and see the effects. If I can find it and it goes well I'll make a separate post of the results.

Another 'What is it?' game

Another 'What is it?' game

Re: Another 'What is it?' game

Re: Another 'What is it?' game