Figure 1: Zigzag line defects and the chirality-specific responses to a chiral vapour.
(a), Schematics of the experimental setup and zigzag line defects in a NLC confined within a microgroove of microwrinkles. Geometrical confinement and hybrid anchoring conditions (indicated by blue double-headed arrows) for a liquid filament of an NLC on a microwrinkle groove are shown. Blue cylinders illustrate the director structures n around different points of the zigzag line defect. The nail symbols (T) indicate the projection of n onto the plane of the surface (the head of the nail comes out of the surface). The definition of the domain lengths lR and lL of the zigzag disclination line is shown. The analyte vapour is injected from a tube nozzle fixed to the substrate. The response is directly monitored by a POM. (b), Typical POM images for balanced and imbalanced zigzag domain lengths upon chiral vapour exposure (Scale bar, 10 μm). A sensitive tint plate is used with the configuration shown as S with the polarizer (P) and analyser (A). When the dissolved chiral molecules have the ability to induce right-/left-handed twist distortions, the length of domains with orange/blue colour increases and the imbalance is readily detected visually. (c), The director profiles below the line defect (The red line corresponds to the line defect, and the director profiles are shown by nail symbols. Yellow and blue regions are those with right-handed and left-handed twist distortions, respectively).
