Photo‐Actuated Chiral Smectic Superstructures

Chirality and hierarchy are two representative features of complex configurations inspiring exotic functions. Chiral additives are adopted to break the mirror symmetry of molecular orientation inside smectic layers, and overcome the restriction on in‐layer helical arrangement by virtue of the surface electroclinic effect. The chirality strength of liquid crystals is regulated via the photo‐isomerization of chiral molecular switch, the doping concentration control, and the mixing of different chiral additives. The dynamic evolution of chiral smectic superstructures leads to the reversible rotation of oily streaks (OSs), and even structural transformation between OSs and focal conic domains is demonstrated. This releases new freedom of chiral hierarchical configurations and may inspire fantastic applications in active optics, sensing, and micro‐manufacturing. A strategy for photo‐actuated chiral smectic superstructures is proposed via in‐layer molecular twist caused by surface electroclinic effect. The chirality of liquid crystals is regulated by the photo‐isomerization of chiral molecular switches and other chiral additives, enabling a reversible rotation of oily streaks. Light‐driven structural transformations are also demonstrated. This work enriches dynamic chiral smectic architectures and inspires fantastic applications.