Liquid Crystal Coatings Switched between Flat and Corrugated Surface Texture

Abstract

The topography of the surface is the local deviations of a surface from a perfectly flat plane. Topographic textures on the surface of coating materials consist of gradual or steep concave or convex steps that may vary from nanometers to a more macroscopic level of micrometers to even millimeters. The use of liquid crystal (LC) networks induces the formation of surface topographies. An additional advantage of using photopolymerized LC networks is that one can choose between varieties of alignment strategies that lead to formation of pre‐programmed surface structures. An interesting feature, already found in the LC networks, is that the thermal expansion of uniaxially oriented LC networks is highly anisotropic. The principle of photo‐activated deformation of LC network films shows resemblance to the deformation induced by heating of structured LC network films. In this case, a copolymerized azobenzene molecule disturbs the order when it transforms from its trans state to the cis state.