What is a Liquid Crystal?
A liquid crystal is a hybrid between (i) a liquid which flows like a fluid and (ii) a crystal which is normally found as a solid, exhibiting short- or long-range symmetry.
What is the structure of PDLC glass?
PDLC smart glass is composed of :
Outermost panels of normal float glass (or sometimes acrylic) sandwiched around:
Inner panels of optically clear PET plastic (polyethylene terephthalate), sandwiched around:
ITO (Indium Tin Oxide) which is a transparent conductor, sandwiched around:
a PDLC core comprised of liquid crystal droplets, suspended in a polymer.
How long time does smart glass/film change from opaque to transparent?
Smart glass/film change in 1/100 second from opaque to transparent and 1/10 second from transparent to opaque.
How does PDLC smart glass work?
With no applied voltage, the liquid crystals are randomly oriented and scatter the light which enters. When an electrical signal is applied, the liquid crystals orient themselves parallel to each other, allowing light through.
Why does PDLC require a polymer?
The polymer allows the liquid crystals to be embedded into a film, which can then be sandwiched between panels of glass or plastic. The polymer has constant optical properties which do not vary across its structure, and hence is considered isotropic.
In contrast, the liquid crystal itself is anisotropic, since its optical characteristics are not constant across its structure, but rather can vary under application of an electric field.