Aligning liquid crystals using self-assembled monolayers

Conventional method of liquid crystal (LC) alignment - rubbing of polyimide film with a cloth [I] - changes the topography of the layer and induces anisotropic orientation of polymer chains along the rubbing direction. Unfortunately, it also generates a lot of debris. Moreover, this method is incompatible with localized control over LC alignment. Recently, anchoring of LC was demonstrated using low energy surfaces from self-assembled monolayers (SAMs) deposited from a liquid phase on gold and silica [2,3]. We applied Molecular Vapor Deposition (MVD (TM)) technology for anchoring of MLC 6610 liquid crystal to ITO surface. Advantage of vapor-phase deposition in superior surface quality has been reported elsewhere [4]. Self-assembled monolayers of perfluorinated chlorosilanes and aminosilanes were used to build LC cell with symmetrical boundary condition and cell gap of 10 mu m. Anchoring energy of 4.2 x 10(-4) J/m(2) was obtained using capacity method for both types of SAMs. M LC 66 10 showed 2.45 V threshold voltage. We observed a uniform vertical alignment of the cell without defects.