55 citations · 251 across the 19 of their papers we have counts for
21 papers
Liquid crystalline order and its impact on shape evolution of fluid lipid membranes
Ingo Nitschke, Maik Porrmann, Axel Voigt
Dynamic approaches to minimize the classical curvature-elasticity free energy for a fluid lipid membrane, are extended towards a Surface Beris--Edwards--Helfrich model. This extens…
Surface Phase-Field-Crystal-Helfrich model for out-of-plane deformations in thin crystalline sheets with lattice mismatch
Emma Radice, Ingo Nitschke, Marco Salvalaglio +1
Thin, flexible crystalline sheets exhibit unique elastic properties due to their ability to undergo out-of-plane deformations. Understanding this behavior requires a description th…
Scalar Truesdell Time Derivative and -- Surface Gradient Flows
Rainer Backofen, Ingo Nitschke, Axel Voigt
We address surface gradient flows which allow for energy dissipation by evolving the surface and a scalar quantity on it, simultaneously. A proper choice of the time derivative and…
Hydrodynamic liquid crystal models for lipid bilayers
Ingo Nitschke, Jan Magnus Sischka, Axel Voigt
Coarse-grained continuous descriptions for lipid bilayers are typically based on minimizing the Helfrich energy. Such models consider the fluid properties of these structures only…
The influence of higher order geometric terms on the asymmetry and dynamics of membranes
Jan Magnus Sischka, Ingo Nitschke, Axel Voigt
We consider membranes as fluid deformable surface and allow for higher order geometric terms in the bending energy. The evolution equations are derived and numerically solved using…
Active nematodynamics on deformable surfaces
Ingo Nitschke, Axel Voigt
We consider active nematodynamics on deformable surfaces. Based on a thermodynamically consistent surface Beris-Edwards model we add nematic activity and focus on the emerging addi…
Beris-Edwards Models on Evolving Surfaces: A Lagrange-D'Alembert Approach
Ingo Nitschke, Axel Voigt
Using the Lagrange-D'Alembert principle we develop thermodynamically consistent surface Beris-Edwards models. These models couple viscous inextensible surface flow with a Landau-de…
Mesoscale modeling of deformations and defects in thin crystalline sheets
Lucas Benoit--Maréchal, Ingo Nitschke, Axel Voigt +1
We present a mesoscale description of deformations and defects in thin, flexible sheets with crystalline order, tackling the interplay between in-plane elasticity, out-of-plane def…
Derivation and simulation of a two-phase fluid deformable surface model
Elena Bachini, Veit Krause, Ingo Nitschke +1
We consider two-phase fluid deformable surfaces as model systems for biomembranes. Such surfaces are modeled by incompressible surface Navier-Stokes-Cahn-Hilliard-like equations wi…
Tensorial time derivatives on moving surfaces: General concepts and a specific application for surface Landau-de Gennes models
Ingo Nitschke, Axel Voigt
Observer-invariance is regarded as a minimum requirement for an appropriate definition of time derivatives. We systematically discuss such time derivatives for surface tensor field…
Tangential Tensor Fields on Deformable Surfaces -- How to Derive Consistent -Gradient Flows
Ingo Nitschke, Souhayl Sadik, Axel Voigt
We consider gradient flows of surface energies which depend on the surface by a parameterization and on a tangential tensor field. The flow allows for dissipation by evolving the p…
Observer-invariant time derivatives on moving surfaces
Ingo Nitschke, Axel Voigt
Observer-invariance is regarded as a minimum requirement for an appropriate definition and derived systematically from a spacetime setting, where observer-invariance is a special c…
A numerical approach for fluid deformable surfaces
Sebastian Reuther, Ingo Nitschke, Axel Voigt
Fluid deformable surfaces show a solid-fluid duality which establishes a tight interplay between tangential flow and surface deformation. We derive the governing equations as a thi…
Properties of surface Landau-de Gennes Q-tensor models
Michael Nestler, Ingo Nitschke, Hartmut Löwen +1
Uniaxial nematic liquid crystals whose molecular orientation is subjected to a tangential anchoring on a curved surface offer a non trivial interplay between the geometry and the t…
Liquid Crystals on Deformable Surfaces
Ingo Nitschke, Sebastian Reuther, Axel Voigt
Liquid crystals with molecules constrained to the tangent bundle of a curved surface show interesting phenomena resulting from the tight coupling of the elastic and bulk free energ…
Comment on Geometrical Control of Active Turbulence in Curved Topographies
Ingo Nitschke, Sebastian Reuther, Axel Voigt
In the recent letter Pearce et. al. Phys. Rev. Lett. 122, 168002 (2019) the authors investigate the turbulent dynamics of a two-dimensional active nematic liquid crystal which is c…
A finite element approach for vector- and tensor-valued surface PDEs
Michael Nestler, Ingo Nitschke, Axel Voigt
We derive a Cartesian componentwise description of the covariant derivative of tangential tensor fields of any degree on general manifolds. This allows to reformulate any vector- a…
Hydrodynamic interactions in polar liquid crystals on evolving surfaces
Ingo Nitschke, Sebastian Reuther, Axel Voigt
We consider the derivation and numerical solution of the flow of passive and active polar liquid crystals, whose molecular orientation is subjected to a tangential anchoring on an…
Nematic liquid crystals on curved surfaces - a thin film limit
Ingo Nitschke, Michael Nestler, Simon Praetorius +2
We consider a thin film limit of a Landau-de Gennes Q-tensor model. In the limiting process we observe a continuous transition where the normal and tangential parts of the Q-tensor…
Discrete exterior calculus (DEC) for the surface Navier-Stokes equation
Ingo Nitschke, Sebastian Reuther, Axel Voigt
We consider a numerical approach for the incompressible surface Navier-Stokes equation. The approach is based on the covariant form and uses discrete exterior calculus (DEC) in spa…
Orientational order on surfaces - the coupling of topology, geometry, and dynamics
Michael Nestler, Ingo Nitschke, Simon Praetorius +1
We consider the numerical investigation of surface bound orientational order using unit tangential vector fields by means of a gradient-flow equation of a weak surface Frank-Oseen…