PDLC film, or Polymer Dispersed Liquid Crystal film, is a switchable smart film that transitions between opaque and transparent states when an electric current is applied or removed. It is made by sandwiching liquid crystal droplets in a polymer matrix between two transparent conductive films, typically Indium Tin Oxide (ITO). When the power is off, the liquid crystals are randomly oriented, making the film opaque; when the power is on, they align with the electric field, allowing light to pass through and making the film transparent.

How it works
Opaque state (power off): The liquid crystal molecules are randomly scattered. When light hits the film, it is scattered in multiple directions, causing the film to appear opaque or frosted.
Transparent state (power on): When an electric current is applied, the liquid crystal molecules align with the electric field. This allows light to pass straight through the film, making it transparent.

Applications
Privacy: PDLC film is widely used to create privacy glass in offices, homes, and other spaces by allowing users to instantly switch between open and private modes.

Retrofitting existing glass: Adhesive PDLC films can be applied to existing windows and glass partitions, providing a lower-cost alternative to replacing the entire unit.

Projection screens: When in its opaque state, the film can be used as a projection surface.

Other uses: PDLC technology is also found in applications like smart windows for buildings and vehicles.