What is a Smart GLASS film, and how does it work?
Updated: Nov 10, 2019
What is a smart glass firm?
A Smart glass film, also called Switchable PDLC film, is a product that is capable of adjusting light transmission between transparent and opaque using AC power. In other words, it is a film that stays translucent in its natural state and switches to transparent in the presence of an electric signal.
How does Smart glass film work?
First of all, let us familiarize ourselves with the components of the smart glass film.
A smart glass film is composed of two elements.
The ITO film (Indium Tin Oxide) and,
The PDLC film
The ITO (Indium Tin Oxide): is a transparent electrical conducting ternary compound. It is composed of Indium, tin and oxygen mixed in varying proportions. The two main properties of Indium Tin Oxide which are: its electrical conductivity and optical transparency, as well as the ease with which it can be deposited as a thin film makes it a suitable compound for the production of smart films. The ITO film's primary function is to conduct electric current to the PDLC film.
The PDLC film: PDLC means Polymer Dispersed Liquid Crystal's. A PDLC film is made up of liquid crystal molecules (microdroplets). These liquid crystal molecules have electrical conducting properties incorporated in them at a nanoscale which allows the crystal to be controlled by an electric volt. The liquid crystals are then dispersed in a polymer substance which has tiny holes that are filled by the liquid crystals.
When electricity is applied to the liquid crystals through the ITO, they scatter or become aligned within the polymer layer. The movement of these liquid crystals within the polymer layer is what produces the opaque and transparent effect of the smart glass film.
Now that you know the two primary components of the smart film. Your next question i believe would be; How do they work?
The PDLC film, in its natural state, appears opaque due to the random orientations of the liquid crystals in the polymer. Once a controlling device sends an electrical signal which is widely conducted by the ITO film, the scattered liquid crystals in the polymer align, allowing light to be absorbed, and the film becomes transparent.
Wikipedia. Smart Film. (July 2016). Retrieved from https://en.wikipedia.org/wiki/Smart_film
Wikipedia. Indium Tin Oxide. (n.d.). Retrieved from https://en.wikipedia.org/wiki/Indium_tin_oxide
Polymer-dispersed Liquid Crystal. (n.d.). Retrieved from https://www.sciencedirect.com/topics/chemistry/polymer-dispersed-liquid-crystal
Image - ITO is a clear, conductive liquid/film and here it was coating on a flexible plastic (PET) sheet. (n.d.). Retrieved from https://www.amazon.com/ITO-Indium-Oxide-Coated-Plastic/dp/B00JFJJ5P8
Image - Operation of a smart PDLC switchable film. CMMPE - University of Cambridge. (n.d.). Retrieved from http://www-g.eng.cam.ac.uk/CMMPE/OldSite/res_mat_pdlc.html