(I) [Inquiry] Analyzing a Commercial Smart Glass Product

[alyami]

TL;DR

Analyzing a commercial smart glass product that switches from semi-transparent (OFF) to fully opaque (ON) with 12V input. Trying to identify if it uses PNLC, Guest-Host LCD, or another tech. It has a black film layer on one side, a transparent layer, and a multi-pin FFC cable. Goal: replicate or improve it with higher transparency and opacity at low cost. Looking for expert input

Hello everybody

I discovered this cover a while ago and I am trying to understand its work and the last thing I found is that it might be PNLC ( Polymer Network Liquid Crystal ) and this is what I often think
Or it is GHLC ( guest-host liquid crystal ) and this is not likely because I think it is more expensive than the PNL
The way it works is when the current is connected to it, it becomes opaque black, and when the current is cut, it returns transparent (relatively)
Also there are two pictures and I am trying to turn it at a 90 degree angle and it turns out that there is a vision
But when you turn it in the other direction, it becomes invisible.

From the pictures, it is clear that there is a small fragile bottle covered with a layer of one side in black, and this is what prompted me to think, is this bottle of the ITO type? Or just a regular PNLC bottle and it was painted from one side
You can notice scattered squares of glass slightly protruding from the top and have been marked in red

I will upload some pictures to clarify the idea for you
Maybe you know what the materials are.
And if you have an idea for something similar and less expensive hello everyone
Thanks for all your efforts

 

[Tom.G]

It is a sheet of Liquid Crystal, as used in flat-screen video displays.
https://en.wikipedia.org/wiki/Liquid-crystal_display

There are also Liquid Crystal sheets available that change color with a magnetic field. Kinda fun to play with -- and can (could?) be used to display the "ones" and "zeros" of the magnetic stripe on credit cards.

Possibly related:
https://en.wikipedia.org/wiki/Smart_glass

Cheers,
Tom

 

[alyami]

Hello, and thank you for this opportunity
I post thread before and remove it bcz I did not clarify the main points i need so here is the new one and try my best to clarify it as i can

I’m currently analyzing a commercial smart glass product that shifts between a semi-transparent state and full opacity depending on electrical input. I’m trying to identify the specific technology used (possibly PNLC, Guest-Host LCD, or another form of LCD), in order to develop a more affordable version with improved optical performance.

When powered off, the panel becomes relatively transparent, and when powered on, it becomes fully opaque, indicating an electric-field-driven optical change.

The product is powered through a 12V input (car-style power) into a converter module, but the output voltage/frequency is unknown — it could involve DC to AC conversion or other modulation techniques

There’s a flat flexible cable (FFC) attached, sometimes with multiple terminal lines, soldered to a thin transparent top layer of the glass. The internal layer structure reveals a black film covering only one side of the panel, possibly for polarization or optical contrast enhancement.


Images: Operating Modes
1. Image showing panel in OFF mode (no power applied)
2. Image showing panel in ON mode (voltage applied)

Images: Panel Broken for Internal Review
3. Broken edge showing structural layering
4. Clear separation of active vs inactive regions after damage
5. Zoomed-in view of fractured cross-section

Images: Wiring and Construction Details
6. Soldered FFC connection to top layer
7. Transparent layer extending beyond dark film surface
8. Side perspective showing film thickness
9. Zoom on outer black film layer

Additional: Multi-pin FFC Cable Examples
10. Closeup of multi-pin FFC cable
11. Alternate angle of multi-terminal cable



Questions:

• Based on the observed behavior and structure, could this be a PNLC-based system, Guest-Host LCD, standard TN/STN LCD, or another optical material altogether?


• What is the likely function of the black film layer applied to one side? Could it be a polarizer, or something else to improve light absorption and contrast?


• Why does the FFC cable sometimes have multiple terminals instead of a basic two-wire system? Could this suggest segmented control or additional electrode structures?


• What is the identity and function of the transparent top layer extending above the black region? Does it suggest that this panel was cut from pre-fabricated sheet stock?


• If one were to design an improved version of this product, which material or technique would provide maximum transparency when off, and maximum opacity with minimal light transmission when on, at lowest possible cost?





Any scientific references, journal papers, or datasheets comparing the behavior and requirements of PNLC, Guest-Host, and LCD technologies would be greatly appreciated


Here is also video shows how it works, you can slow the video to see the edges down how it work when he cut the power
About the logo i found he use mate-film cut but its not matter now

Vid link :


Thank you in advance for your insights!

 

[Tom.G]

Sorry about the late reply!

As for the low brightness/contrast, that would be due to the layer of polarizing plastic. This blocks transmission of about 75% the light.

Unfortunately, since the members here are volunteers, and many long retired, we are not in a position to do a complete product development project for your device.

Perhaps you could find an electro-optical engineer that would be willing to join you as a partner, with you supplying the funds and (s)he supplying the technical aspects.

Cheers,
Tom

p.s. please keep us updated on your progress!

 

[berkeman]

When powered off, the panel becomes relatively transparent, and when powered on, it becomes fully opaque, indicating an electric-field-driven optical change.

• If one were to design an improved version of this product, which material or technique would provide maximum transparency when off, and maximum opacity with minimal light transmission when on, at lowest possible cost?

I just realized that you are asking to improve a product that is illegal in most countries. Obscuring the license plate of a motor vehicle (especially on-the-fly from the driver's seat while driving) does not have valid/legal applications. Thread is closed.

 

[berkeman]

After a PM conversation with the OP, he is actually working on a different application, so this thread is reopened provisionally.

 

[Rive]

The way it works is when the current is connected to it, it becomes opaque black, and when the current is cut, it returns transparent (relatively)

You need to carefully think through the 'off' state matching to the application

And if you have an idea for something similar and less expensive

It's hard to guess what would be cheaper for an use without knowing at least something about that use.
Smart films (self-adhesive) are relative cheap (and flexible).