In this paper is presented the world of the liquid crystals: what they are and how the liquid-crystaline mesophases are characterized and their applications. The existing phenomenological theories are discussed, as well as, the boundary surface effects. In addition, the functioning mode of a liquid crystal display is shown, where the involved physical phenomenon are discussed. At the end is presented a way to construct a display, which can be used in classes.
liquid crystal; surface effects; display