Spatially confined liquid crystals exhibit non-uniform alignment, often accompanied by selforganised topological defects of non-trivial shape in response to imposed boundary conditionsand geometry. Here we show that a nematic liquid crystal, when confined in a sinusoidalmicrowrinkle groove, exhibits a new periodic arrangement of twist deformations and a zigzagline defect. This periodic ordering results from the inherent liquid crystal elastic anisotropy andthe antagonistic boundary conditions at the flat liquid crystal–air and the curved liquid crystal–groove interfaces. The periodic structure can be tuned by controlling the groove geometryand the molecular chirality, which demonstrates the importance of boundary conditions andintroduced asymmetry for the engineering of topological defects. moreover, the kinks in thezigzag defects can trap small particles, which may afford a new method for manipulationof colloids. our system, which uses easily fabricated microwrinkle grooves, provides a newmicrofabrication method based on the arrangement of controllable defects.
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