Humidity-Responsive Blue Phase Liquid-Crystalline Film with Reconfigurable and Tailored Visual Signals

Liquid-crystalline polymers have been applied to a wide variety of stimuli-responsive materials; however, the inevitable mesogenic alignment or extra complicated preparation hinders their further application and large-scale fabrication. Here, fabrication of free-standing blue phase liquid-crystalline (BPLC) film is reported by using one well-designed system composed of specially designed hydrogen-bonded mesogenic precursors, which can spontaneously self-assemble into 3D nanostructures without additional orientation treatment. Upon corrosion in alkaline solution, the BPLC film shows reversible humidity-responsive behaviors by manipulating their lattice parameters of the nanostructures. The unique stimuli-responsive behaviors originate from tunable 3D periodic nanostructures of soft materials are reprogrammable, reconfigurable, and visual, showing their potentials for advanced applications as sensor, display, and anticounterfeiting.