Controllable liquid crystal alignment with the assistance of reactive monomers is realized by the Surface Localized Polymer Alignment (SLPA) system. The SLPA system allows fully controllable liquid crystal pretilt angles, which could open new types of liquid crystal device fabrication techniques.
The SLPA method not only allows a fully controllable pretilt angle, but also allows different pretilt angles to be set in different areas. More specifically, the concept of this type of alignment is to polymerize a low concentration of reactive mesogens in a liquid crystal cell while a voltage is applied.
In the SLPA system, the polymer layer is designed to be only present on the cell surface. Since most of monomers are polymerized on the cell surface and form a rigid polymer layer which is preferably less than a wavelength of light in thickness, the light scattering issue can be solved.