Liquid Crystal Smart Film is a liquid crystal (LC) product based on polymer dispersed liquid crystal (PDLC) technology and two semiconductor films of indium tin oxide (ITO) films used as electrodes. Thermoplastic protective layers (PET) are used to protect the film from scratches. The transparency of the smart film can be controlled by AC current. Smart film is produced in two types - self-adhesive, which can be aplied to ordinary glass, and non-adhesive film, used for the production of smart glass.
Smart Film structure
The self-adhesive smart film on liquid crystals has several layers, as shown in the figure below.
Non-adhesive smart film on liquid crystal has several layers, as shown in the figure below.
The principle of operation of smart film
A polymer-dispersed liquid crystal is simply micro-droplets of liquid crystals encapsulated in a polymer matrix. Liquid crystals react to an electric charge. In a static state, liquid crystal molecules remain in a random configuration, which refracts the light that penetrates the mixture, making it opaque. When electricity is supplied, the molecules line up in the direction of the electric field, which allows light to pass through what is now essentially a transparent surface. When the electric charge is turned off, the liquid crystal droplets again become randomly oriented and the incoming light is again strongly scattered and does not pass through the mixture in the usual way, as a result of which it completely blocks the image.
Liquid crystal technology is familiar to flat panel displays. A liquid crystal display, or LCD, is the most popular flat panel display technology we see in laptop computers, cell phones, calculators, digital clocks, gas pumps, etc. In LCD displays, the supplied electricity changes the shape of the liquid crystals to allow light to pass through the individual elements, thus forming images, drawings and numbers on the displays.