Spontaneous radial liquid crystals alignment on curved polymeric surfaces

We report on the fabrication and characterization of curved periodic microstructures formed through the controlled phase separation of a liquid crystal and a polymerizing matrix comprising self-aligned liquid crystal. Imaging through a "Fresnel like" structure imparts an intensity profile onto a photosensitive mixture which subsequently forms periodic alternating curved polymeric and liquid crystal slices. The phase separated concentric rings of nematic liquid crystal self-align in a radial alignment in between the polymer walls as indicated by polarizing optical microscopy analysis (Maltese cross). Electro-optical experiments confirm the possibility to control this alignment and the optical properties of the macroscopic structure by means of a quite low external voltage. The system exhibits high-quality and self-alignment of an ordered (liquid crystal) fluid without the need of surface chemistry or functionalization. © 2014 AIP Publishing LLC