198 citations · 1.8k across the 37 of their papers we have counts for
28 papers · 1 filter
Competing routes to spontaneous flow in confined active nematics
Rahil N. Valani, Vedad Dzanic, Sumesh P. Thampi +1
Active nematics can spontaneously develop flow beyond a critical activity in confined geometries. We show analytically that the onset of flow is governed by two competing instabili…
Active flows drive anchoring of nematics at rigid walls
Michael Fang, Ioannis Hadjifrangiskou, Sumesh P. Thampi +2
Although confinement strongly influences flows in active materials, it remains unclear how active particles align at rigid boundaries when no thermodynamic anchoring is imposed. We…
Low-Pass Filtering of Active Turbulent Flows to Liquid Substrates
Gianmarco Spera, Julia M. Yeomans, Sumesh P. Thampi
To study the impact of active systems on their surroundings, we introduce a model that couples an active nematic fluid to an isotropic substrate fluid via friction. We numerically…
From Equilibrium Multistability to Spatiotemporal Chaos in Channel Flows of Nematic Fluids
Rahil N. Valani, Sumesh Thampi, Julia M. Yeomans
We investigate channel-confined, nematic liquid crystals using the Beris-Edwards model of nematohydrodynamics. Using strong homeotropic anchoring at the walls, we find multistabili…
Why Extensile and Contractile Tissues Could be Hard to Tell Apart
Jan Rozman, Sumesh P. Thampi, Julia M. Yeomans
Active nematic models explain the topological defects and flow patterns observed in epithelial tissues, but the nature of active stress-whether it is extensile or contractile, a ke…
Active sorting to boundaries in active nematic -- passive isotropic fluid mixtures
Saraswat Bhattacharyya, Julia M. Yeomans
We use a two-fluid model to study a confined mixture of an active nematic fluid and a passive isotropic fluid. We find that an extensile active fluid preferentially accumulates at…
Spontaneous Hole Formation in Cell Monolayers Emerges from Collective Cell Motion
Diogo E. P. Pinto, Jan Rozman, Julia M. Yeomans
Although cell monolayers typically remain confluent, they can spontaneously develop persistent holes as a result of collective cellular motion. Recent studies on MDCK monolayers cu…
Coarse-graining dense, deformable active particles
Mehrana R. Nejad, Julia M Yeomans
We coarse-grain a model of closely-packed ellipses that can vary their aspect ratio to derive continuum equations for materials comprising confluent deformable particles such as ep…
Cell Sorting in an Active Nematic Vertex Model
Jan Rozman, Julia M. Yeomans
We study a mixture of extensile and contractile cells using a vertex model extended to include active nematic stresses. The two cell populations phase separate over time. While pha…
Vertex model with internal dissipation enables sustained flows
Jan Rozman, Chaithanya K. V. S., Julia M. Yeomans +1
Complex tissue flows in epithelia are driven by intra- and inter-cellular processes that generate, maintain, and coordinate mechanical forces. There has been growing evidence that…
Hydrodynamics of Micro-swimmers in Films
Arnold J. T. M. Mathijssen, Amin Doostmohammadi, Julia M. Yeomans +1
One of the principal mechanisms by which surfaces and interfaces affect microbial life is by perturbing the hydrodynamic flows generated by swimming. By summing a recursive series…
A circle swimmer at low Reynolds number
Rodrigo Ledesma-Aguilar, Hartmut Loewen, Julia M. Yeomans
Swimming in circles occurs in a variety of situations at low Reynolds number. Here we propose a simple model for a swimmer that undergoes circular motion, generalising the model of…
Confinement of knotted polymers in a slit
R. Matthews, A. A. Louis, J. M. Yeomans
We investigate the effect of knot type on the properties of a ring polymer confined to a slit. For relatively wide slits, the more complex the knot, the more the force exerted by t…
Complex dynamics of knotted filaments in shear flow
R. Matthews, A. A. Louis, J. M. Yeomans
Coarse-grained simulations are used to demonstrate that knotted filaments in shear flow at zero Reynolds number exhibit remarkably rich dynamic behaviour. For stiff filaments that…
Effect of topology on dynamics of knots in polymers under tension
R. Matthews, A. A. Louis, J. M. Yeomans
We use computer simulations to compare the dynamical behaviour of torus and even-twist knots in polymers under tension. The knots diffuse through a mechanism similar to reptation.…
Numerical Results for the Blue Phases
G. P. Alexander, J. M. Yeomans
We review recent numerical work investigating the equilibrium phase diagram, and the dynamics, of the cholesteric blue phases. In equilibrium numerical results confirm the predicti…
Dumb-bell swimmers
G. P. Alexander, J. M. Yeomans
We investigate the way in which oscillating dumb-bells, a simple microscopic model of apolar swimmers, move at low Reynold's number. In accordance with Purcell's Scallop Theorem a…
Flexoelectric blue phases
G P Alexander, J M Yeomans
We describe the occurence and properties of liquid crystal phases showing two dimensional splay and bend distortions which are stabilised by flexoelectric interactions. These phase…
Swimming with a friend at low Reynolds number
C. M. Pooley, G. P. Alexander, J. M. Yeomans
We investigate the hydrodynamic interactions between microorganisms swimming at low Reynolds number. By considering simple model swimmers, and combining analytic and numerical appr…
Stabilising the Blue Phases
G. P. Alexander, J. M. Yeomans
We present an investigation of the phase diagram of cholesteric liquid crystals within the framework of Landau - de Gennes theory. The free energy is modified to incorporate all th…
Polymer packaging and ejection in viral capsids: shape matters
I. Ali, D. Marenduzzo, J. M. Yeomans
We use a mesoscale simulation approach to explore the impact of different capsid geometries on the packaging and ejection dynamics of polymers of different flexibility. We find tha…
Hydrodynamics of topological defects in nematic liquid crystals
Geza Toth, Colin Denniston, Julia M. Yeomans
We show that back-flow, the coupling between the order parameter and the velocity fields, has a significant effect on the motion of defects in nematic liquid crystals. In particula…
Polymer collapse in the presence of hydrodynamic interactions
N. Kikuchi, A. Gent, J. M. Yeomans
We investigate numerically the dynamical behaviour of a polymer chain collapsing in a dilute solution. The rate of collapse is measured with and without the presence of hydrodynami…
Phase Ordering in Nematic Liquid Crystals
Colin Denniston, Enzo Orlandini, J. M. Yeomans
We study the kinetics of the nematic-isotropic transition in a two-dimensional liquid crystal by using a lattice Boltzmann scheme that couples the tensor order parameter and the fl…