How does an electric field change the orientation of molecules in a nematic liquid crystal?

In a nematic liquid crystal, molecules possess a preferred orientation known as the director. When an electric field is applied to the material, it exerts a force that influences this alignment.12

Depending on the specific chemical structure of the liquid crystal molecules, they will reorient themselves to align either parallel or perpendicular to the direction of the applied field. This process, known as an electro-optical effect, occurs because the molecules are sensitive to the field's influence, allowing them to shift from their initial state—such as a twisted alignment—to a new orientation dictated by the field.213

This ability to manipulate molecular orientation is fundamental to the operation of liquid crystal displays. By switching the electric field on or off, the orientation of the molecules changes, which in turn alters how the material interacts with polarized light, effectively controlling whether light passes through the display or is blocked.32