Stable nematic droplets with handles

Abstract

We stabilize nematic droplets with handles against surface-tension-driven instabilities using a yield-stress material as outer fluid and study the complex nematic textures and defect structures that result from the competition between topological constraints and the elasticity of the nematic liquid crystal. We uncover a surprisingly persistent twisted configuration of the nematic director inside the droplets when tangential anchoring is established at their boundaries, which we explain after considering the influence of saddle-splay on the elastic free energy. For toroidal droplets, we find that the saddle-splay energy screens the twisting energy resulting in a spontaneous breaking of mirror symmetry; the chiral twisted state persists for aspect ratios as large as ~20. For droplets with additional handles, we observe in experiments and computer simulations that there are two additional -1 surface defects per handle; these are located in regions with local saddle geometry to minimize the nematic distortions and hence the corresponding elastic free energy.

23 pages, 4 figures, PNAS (2013)

References in corpus (7)

• Reconfigurable knots and links in chiral nematic colloids
• Two-Dimensional Matter: Order, Curvature and Defects
• Topological colloids
• Disclination Loops, Hedgehogs, and All That
• Nematic textures in spherical shells
• Topological Defects in Spherical Nematics
• Filling the void in confined polymer nematics: phase transitions in a minimal model of dsDNA packing

Cited by in corpus (17)

• Interpretation of saddle-splay and the Oseen-Frank free energy in liquid crystals
• Chiral structures and defects of lyotropic chromonic liquid crystals induced by saddle-splay elasticity
• Phase nucleation in curved space
• Vortex formation and dynamics of defects in shells of active nematics
• The geometry of thresholdless active flow in nematic microfluidics
• Lassoing saddle splay and the geometrical control of topological defects
• Equilibrium configurations of nematic liquid crystals on a torus
• Hydrodynamic theory for nematic shells: the interplay among curvature, flow and alignment
• Point Defects, Chirality and Singularity Theory in Cholesteric Liquid Crystal Droplets
• Retrieving the saddle-splay elastic constant $K_{24}$ of nematic liquid crystals from an algebraic approach
• Piezoelectric truss metamaterials: data-driven design and additive manufacturing
• Observation of the resonance frequencies of a stable torus of fluid
• Experimental Dispersion Relation of Surface Waves Along a Torus of Fluid
• Curvature-driven stability of defects in nematic textures over spherical disks
• Nematic liquid crystals on sinusoidal channels: the zigzag instability
• Nematic droplets at fibres
• Harmonic field in knotted space