Pattern formation in hybrid cholesteric films with modulated planar surface

Under simultaneously tangential and perpendicular alignment, known as hybrid alignment, chiral nematic liquid crystals with specific pitch lengths form a striped pattern with significant potential for applications such as diffraction gratings. This study employs computer simulations to investigate methods for fabricating different striped patterns using substrates with a predesigned organisation of the easy axis on the planar (tangential) surface. The substrate designs include chequerboard, circular, and triangular patterns, with the easy axis oriented perpendicularly in alternating regions. The number of domains with a given pattern varies, and the resulting changes in the stripe pattern, including the system’s elastic energies, are analysed. The simulations demonstrate the feasibility of controlling the formation of complex patterns through simple modifications of the planar substrate.