Hierarchical Helical Structure of Cholesteric Liquid Crystals Enabled Localized Optical/Mechanical Control with Nanoscale Precision

Chirality is a geometric property that naturally occurs at all levels in biological systems and has unique ability to introduce functionalities such as selective reflection of light, mechanical adaption, and resistance against external stresses.Numerous efforts have been made to mimic such morphologies and their properties in synthetic materials. Chiral nematic phase of Liquid Crystals is known to form elegant and distinct structures across length scales resembling the chiral structure omnipresent in living systems such as the exoskeletons of beetle, plant tissues and others. In this work, we relied on chemically nano-patterned substrate with varying anchoring energy to self-assemble uniform lying down helices which directs the formation of hierarchical helical structure at room temperature. The twisted rope like nature of this morphology was investigated using different parameters to gain control over the structure and its properties while polymerization was used to generate a soft template. The study provides a potential avenue to design and fabricate miniaturized or wearable devices, which requires delicate control of optical and mechanical properties with nanoscale precision.