Are PDLCs only available as artificial materials?
Not at all; common examples of natural occurrences of liquid crystals include proteins, soaps, detergents, and even some types of clay.
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.
Can smart glass/film be regulated to gradually change its state?
Yes, smart glass/film can be regulated to slowly transform from opaque to transparent or vice versa. A transformer with dimmer function is needed.
Why is PDLC considered to be smart?
The smartness of PDLCs is a result of its ability to change its transparency (technically called the transmittance) when an electrical stimulus is applied to it. This is normally by way of an alternating voltage, which exerts an alternating electric field across the PDLC material.
Nevertheless, the PDLC is only as smart as the control system which stimulates the change, which can be driven by a push button switch, a light sensor, or a building automation system.
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.