Assembly and transport of nematic colloidal swarms above photo-patterned defects and surfaces

We investigate the dynamic assembly and swarm translocation of anisometric colloidal particles dispersed in a nematic liquid crystal and driven above a photosensitive surface. We use liquid crystal-enabled electrophoresis to propel these particles via an alternating electric field perpendicular to t...

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Bibliographic Details
Authors: Straube, Arthur V., Pagès Casas, Josep M., Ortiz-Ambriz, Antonio, Tierno, Pietro, Ignés i Mullol, Jordi, Sagués i Mestre, Francesc
Format: article
Status:Published version
Publication Date:2018
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/127850
Online Access:https://hdl.handle.net/2445/127850
Access Level:Open access
Keyword:Col·loides
Cristalls líquids
Colloids
Liquid crystals
Description
Summary:We investigate the dynamic assembly and swarm translocation of anisometric colloidal particles dispersed in a nematic liquid crystal and driven above a photosensitive surface. We use liquid crystal-enabled electrophoresis to propel these particles via an alternating electric field perpendicular to the sample cell. By manipulating the anchoring conditions on one surface of the experimental cell, we obtain a spatially extended spiral pattern of the liquid crystal orientation that induces the dynamic assembly of a rotating colloidal mill. This structure can be transported by translocating the topological defect above the photosensitive surface. We complement our findings with a theoretical model that captures the basic physics of the process, by formulating an analytic equation for the director field above the surface. Our reconfigurable nematic assemblies may be used as a test bed for complex swarming behaviour in biological and artificial microscale systems.