Liquid crystals are substances that have liquid and crystalline properties. They resemble viscous liquids in their flow properties, but also exhibit the physical behavior of crystals.
Due to the combination of properties, on the one hand the flow properties of a liquid, on the other hand the structure of crystals, liquid crystals can be used in light refraction, light blocking and reflection
. In other words, in applications such as those required in LC switches, LCD displays and LCD projectors
. The properties of liquid crystals are based on thermal effects as an intermediate phase between the solid, crystalline state and the liquid state. Certain substances can assume different liquid crystalline states with increasing temperature, which is due to the change in molecular structure.