Surface alignment of liquid crystal by direct laser writing

Abstract

We demonstrate the fabrication of high-quality surface alignment layers on glass using Direct Laser Writing with a 2-photon polymerisation technique. Commercial photosensitive resins are utilized to print alignment layers by scanning a femtosecond laser focal point near the resin-glass interface, resulting in ~100 nm thin layers. These layers provide good planar anchoring for nematic liquid crystals, with an easy axis of alignment along the scanning direction. The azimuthal anchoring strength is comparable to commercial rubbed polyimide layers. This method offers flexibility, enabling fast printing of complex shapes with arbitrary alignment patterns not only in 2D but also in 3D.