Tunable Topological Defect Patterns: Tunable Dynamic Topological Defect Pattern Formation in Nematic Liquid Crystals (Advanced Optical Materials 1/2020)

Using a combination of elastic interactions and response to an oscillating electric field, MinSu Kim and Francesca Serra create switchable patterns of topological defects in nematic liquid crystals (see article number 1900991). The authors tune the spacing between defects with the amplitude and frequency of the field, and use micro-pillars to pin the location of some defects, while letting the others free to arrange. Defects modulate the refractive index, therefore with this strategy switchable diffraction gratings are created.