Vortex formation and dynamics of defects in active nematic shells
We present a hydrodynamic model for a thin spherical shell of active nematic liquid crystal with an arbitrary configuration of defects. The active flows generated by defects in the director lead to the formation of stable vortices, analogous to those seen in confined systems in flat geometries, whic...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aa89aa |
| _version_ | 1797750574485078016 |
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| author | Diana Khoromskaia Gareth P Alexander |
| author_facet | Diana Khoromskaia Gareth P Alexander |
| author_sort | Diana Khoromskaia |
| collection | DOAJ |
| description | We present a hydrodynamic model for a thin spherical shell of active nematic liquid crystal with an arbitrary configuration of defects. The active flows generated by defects in the director lead to the formation of stable vortices, analogous to those seen in confined systems in flat geometries, which generate effective dynamics for four +1/2 defects that reproduces the tetrahedral to planar oscillations observed in experiments. As the activity is increased and two counterrotating vortices dominate the flow, the defects are drawn more tightly into pairs, rotating about antipodal points. We extend this situation to also describe the dynamics of other configurations of defects. For example, two +1 defects are found to attract or repel according to the local geometric character of the director field around them and the extensile or contractile nature of the material, while additional pairs of opposite charge defects can give rise to flow states containing more than two vortices. Finally, we describe the generic relationship between defects in the orientation and singular points of the flow, and suggest implications for the three-dimensional nature of the flow and deformation in the shape of the shell. |
| first_indexed | 2024-03-12T16:34:46Z |
| format | Article |
| id | doaj.art-b2797194f0d84cc8a6cec5d464c40c8e |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:34:46Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-b2797194f0d84cc8a6cec5d464c40c8e2023-08-08T14:56:27ZengIOP PublishingNew Journal of Physics1367-26302017-01-01191010304310.1088/1367-2630/aa89aaVortex formation and dynamics of defects in active nematic shellsDiana Khoromskaia0https://orcid.org/0000-0003-2597-6336Gareth P Alexander1Department of Physics and Centre for Complexity Science, University of Warwick , Coventry CV4 7AL, United KingdomDepartment of Physics and Centre for Complexity Science, University of Warwick , Coventry CV4 7AL, United KingdomWe present a hydrodynamic model for a thin spherical shell of active nematic liquid crystal with an arbitrary configuration of defects. The active flows generated by defects in the director lead to the formation of stable vortices, analogous to those seen in confined systems in flat geometries, which generate effective dynamics for four +1/2 defects that reproduces the tetrahedral to planar oscillations observed in experiments. As the activity is increased and two counterrotating vortices dominate the flow, the defects are drawn more tightly into pairs, rotating about antipodal points. We extend this situation to also describe the dynamics of other configurations of defects. For example, two +1 defects are found to attract or repel according to the local geometric character of the director field around them and the extensile or contractile nature of the material, while additional pairs of opposite charge defects can give rise to flow states containing more than two vortices. Finally, we describe the generic relationship between defects in the orientation and singular points of the flow, and suggest implications for the three-dimensional nature of the flow and deformation in the shape of the shell.https://doi.org/10.1088/1367-2630/aa89aaactive nematicsthin filmtopological defectsspherical shellactive matter |
| spellingShingle | Diana Khoromskaia Gareth P Alexander Vortex formation and dynamics of defects in active nematic shells New Journal of Physics active nematics thin film topological defects spherical shell active matter |
| title | Vortex formation and dynamics of defects in active nematic shells |
| title_full | Vortex formation and dynamics of defects in active nematic shells |
| title_fullStr | Vortex formation and dynamics of defects in active nematic shells |
| title_full_unstemmed | Vortex formation and dynamics of defects in active nematic shells |
| title_short | Vortex formation and dynamics of defects in active nematic shells |
| title_sort | vortex formation and dynamics of defects in active nematic shells |
| topic | active nematics thin film topological defects spherical shell active matter |
| url | https://doi.org/10.1088/1367-2630/aa89aa |
| work_keys_str_mv | AT dianakhoromskaia vortexformationanddynamicsofdefectsinactivenematicshells AT garethpalexander vortexformationanddynamicsofdefectsinactivenematicshells |