Active Solids: Topological Defect Self-Propulsion Without Flow

Fuente: arXiv
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Main Authors: Brauns, Fridtjof, O'Leary, Myles, Hernandez, Arthur, Bowick, Mark J., Marchetti, M. Cristina
Format: Preprint
Published: 2025
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_version_ 1866918116279189504
author Brauns, Fridtjof
O'Leary, Myles
Hernandez, Arthur
Bowick, Mark J.
Marchetti, M. Cristina
author_facet Brauns, Fridtjof
O'Leary, Myles
Hernandez, Arthur
Bowick, Mark J.
Marchetti, M. Cristina
contents The self-propulsion of +1/2 topological defects is a hallmark of active nematic fluids, where the defects are advected by the flow field they themselves generate. In this paper we propose a minimal model for defect self-propulsion in a nematic active solid: a linear elastic medium with an embedded nematic texture that generates active stress and associated elastic strains. We show that such coupling gives rise to self-propelled +1/2 defects that move relative to the elastic medium by local remodeling of the nematic texture without advection. This mechanism is fundamentally different from the fluid case and can lead to unbinding of defect pairs and stabilization of +1 defects. Our findings might help explain how orientational order, of, for example, muscle fibers, is reconfigured during morphogenesis in solid-like tissues. The proposed mechanism may, for instance, control motility and merging of +1/2 defects, which play a crucial role in setting up the body axis during Hydra regeneration.
format Preprint
id arxiv_https___arxiv_org_abs_2502_11296
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Active Solids: Topological Defect Self-Propulsion Without Flow
Brauns, Fridtjof
O'Leary, Myles
Hernandez, Arthur
Bowick, Mark J.
Marchetti, M. Cristina
Soft Condensed Matter
Pattern Formation and Solitons
The self-propulsion of +1/2 topological defects is a hallmark of active nematic fluids, where the defects are advected by the flow field they themselves generate. In this paper we propose a minimal model for defect self-propulsion in a nematic active solid: a linear elastic medium with an embedded nematic texture that generates active stress and associated elastic strains. We show that such coupling gives rise to self-propelled +1/2 defects that move relative to the elastic medium by local remodeling of the nematic texture without advection. This mechanism is fundamentally different from the fluid case and can lead to unbinding of defect pairs and stabilization of +1 defects. Our findings might help explain how orientational order, of, for example, muscle fibers, is reconfigured during morphogenesis in solid-like tissues. The proposed mechanism may, for instance, control motility and merging of +1/2 defects, which play a crucial role in setting up the body axis during Hydra regeneration.
title Active Solids: Topological Defect Self-Propulsion Without Flow
topic Soft Condensed Matter
Pattern Formation and Solitons
url https://arxiv.org/abs/2502.11296