Switching surface topographies based on liquid crystal network coatings

The surface topography of materials is the local deviations of a surface from a perfectly flat plane. This chapter proposes the use of liquid crystal (LC) networks to induce the formation of surface topographies. The driving principle is the light‐triggered trans‐to‐cis isomerization of a copolymerized azobenzene molecule added in a relatively low concentration to the network. An additional advantage of the use of photopolymerized LC networks is that one can chose between a variety of alignment strategies, which leads to the formation of preprogrammed surface structures. The principle of photoactivated deformation of LC network films has many parallels with 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. The formation of LC polymeric networks by in situ polymerization of LC monomers provides the possibility to create films or coatings with director patterns.