Advice on making a liquid crystal screen (shutter)

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Discussion Overview

The discussion revolves around the process of creating a homemade liquid crystal screen, specifically focusing on the assembly of a "smart film" using liquid crystals, UV curable resin, and glass bead spacers. Participants explore various methods and challenges related to curing and achieving uniform thickness in the film.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes their process of mixing liquid crystal with UV curable resin and using glass bead spacers to create a uniform thickness for their smart film, expressing concerns about achieving the necessary pressure during UV curing.
  • Another participant questions the assembly process, seeking clarification on whether the UV curing seals just the edges or cures the entire LCD mixture.
  • A suggestion is made to use a "slip sheet," such as wax paper, between the glass slab and the work to prevent adhesion issues during the curing process.
  • Another participant agrees with the slip sheet suggestion, indicating it may be a viable solution to the adhesion problem.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the assembly process and the curing method. There is no consensus on the best approach to prevent adhesion or achieve uniform thickness, indicating ongoing exploration of the topic.

Contextual Notes

Participants have not fully resolved the challenges related to curing and adhesion, and there are assumptions about the effects of using different materials for the baseplate and slip sheets.

wosoka
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I need to make my own smart film for some experiments.

I've read enough articles on it to know the required components, how they are mixed and applied.

I have a 1:1 mixture of liquid crystal and UV curable resin and glass bead spacers that I need to apply between two ITO PETs and UV cure to bond all the layers together. Glass spacers are used to get unform thickness which is needed for uniform opacity/transparency.
This will create a "smart film".

This is probably done industrially by precision rollers and very powerful UV light to cure it immediately as it leaves the rollers, but I don't have access to such equipment.
Any ideas what else I can try?

If I squeeze the layers and release before UV curing I fear the thickness of the liquid crystal layer will increase back a little. So I probably need pressure applied while the UV glue inside the mixture is being cured by UV light.

I could squeeze the layers with a thick glass slab and use powerful UV LEDs to cure the liquid layer, but I fear the liquid leaked from the sides may adhere the glass slab to it. That could still be removed with an exacto knife but it may easily adhere to the baseplate as well, leaving it stuck between the two.

If I apply some powder or oil which will prevent adhesion to the glass slab and/or baseplate, it may affect the flat surface of the slabs required to cause the spacers inside the mixture to create a uniform 20 micron thickness across the sheet, as the outer layers of the "smart film" are plastic (PET) and not rigid glass. But I may be wrong on this, just an assumption.

Another option may be using some rigid material for a baseplate which doesn't get glue (UV curable resin) adhered to it. I am not aware of such material.

I've already tried without glass spacers and perfect layer thickness and just hand squeezing but the fading speed and opacity is not uniform across the sheet which is a requirement for my experiments.

Any ideas?
 
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I'm not understanding your assembly process yet. It sounds like you are using an IR UV cure to seal the LCD sandwich together? Does that seal just the edges, or does it somehow cure the whole LCD mixture? It's been a while since I worked with LCDs, but I'm more used to edge seals and a liquid in the middle of the panel with the spacers...

http://www.liquidcrystaltechnologies.com/images/LCDCross.gif
LCDCross.gif


EDIT -- Fixed IR cure --> UV cure in my post above.
 

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wosoka said:
but I fear the liquid leaked from the sides may adhere the glass slab to it.
Use a "slip sheet" between your work and the glass slab. I have often used a sheet of ordinary household Wax Paper. It is readily available in grocery stores here in the USA at least.
 
Tom.G said:
Use a "slip sheet" between your work and the glass slab. I have often used a sheet of ordinary household Wax Paper. It is readily available in grocery stores here in the USA at least.
Sounds like that will work.
 

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