Light‐Directed Molecular‐to‐Device Perspective in Azobenzene‐Based Liquid Crystalline Soft Materials

Azobenzene is a prototypical photoresponsive molecule that undergoes reversible trans ‐to‐ cis isomerization upon light irradiation, accompanied by substantial changes in dipole moment, molecular geometry, and intermolecular interactions. These photoinduced molecular‐level transformations can be amplified across hierarchical liquid crystal (LC) assemblies, enabling precise control of mesophase transitions, structural alignment, and macroscopic material properties. Recent advances in molecular engineering have extended the role of azobenzene from simple molecular switches to versatile building blocks for hierarchically ordered and reconfigurable soft materials. This review highlights how the incorporation of azobenzene into nematic, smectic, columnar, and helical LC mesophases enables tunable optical, mechanical, electrochemical, and energy‐related responses. Emerging applications are discussed across various fields, including smart windows with dynamic light modulation, polarization‐dependent optical sensors, light‐driven soft robotic actuators, and molecular solar thermal storage systems. By connecting fundamental photochemical mechanisms with device‐level performance, azobenzene‐LC systems demonstrate how molecular‐level responsiveness can be translated into programmable, multifunctional, and scalable materials. This review provides an integrated molecular‐to‐device perspective on the design principles, current challenges, and future opportunities in azobenzene‐based liquid crystal systems, with the aim of stimulating future advances in light‐controlled soft matter technologies.