Résumé:

The fabrication of novel materials with revolutionary technological applications, such as photonic crystals with large band gaps or metamaterials, could perhaps be based on colloidal particles. However, common particles lack the ability to interact along specic directions, which is needed to build colloidal crystals with desired structures. A possibility is to use either anisotropic building blocks, or to induce tunable directionality and controllable valence of building blocks [1]. Liquid crystal shells oer a way to induce controllable valence by using double emulsions of nematic liq- uid crystal in a host liquid [2,3]. The nematic liquid crystal is an anisotropic medium with local orientational order that exhibits topological singularities (defects). And it is by functionalizing these singularities with linkers, that one could induce directional interactions and bonds between the colloidal particles. Here, we study theoretically and experimentally, the behaviour of microspheres trapped to a spher- ical nematic shell [4]. We demonstrate dierent { director and defect { organizations around a sin- gle particle, such as congurations where the colloidal particle is accompanied by an escaped