1. Reminders

As their name suggests, liquid crystals are liquids characterized by a particular orientation of the molecules [A 1 325] , which translates on a macroscopic scale into a crystal-like anisotropy: the physical properties of the materials depend on the average local molecular orientation.

In the case of nematic liquid crystals, the molecules orient themselves parallel to one another while remaining randomly distributed in the volume. The orientation mechanism relies on very long-range molecular interactions, with the orientation of the liquid crystal within a point propagating over tens...