Geometry in Nature
 
 
 
Home
Research
Vita
Publications
Links
Contact
 


 
 

Publications

  1. Articles in scientific journals
  2. Books
  3. Theses

 

See also profiles on Publons, Orcid or Google Scholar.

 

 

1. Articles in scientific journals

  •  

    Conformational Space of the Translocation Domain of Botulinum Toxin: Atomistic Modeling and Mesoscopic Description of the Coiled-Coil Helix Bundle

    Alexandre Delort, Grazia Cottone, Thérèse E. Malliavin, Martin Michael Müller

    Abstract     

    Int. J. Mol. Sci., 25: 2481, 2024.

     


  •  

    Flexoelectric fluid membrane vesicles in spherical confinement

    Niloufar Abtahi, Lila Bouzar, Nadia Saidi-Amroun, Martin Michael Müller
    EPL, 131(1): 18001, 2020. See also arXiv:2006.04475.

     


  •  

    Isometric bending requires local constraints on free edges

    Jemal Guven, Martin Michael Müller, Pablo Vázquez-Montejo
    Math. Mech. Solids, 24: 4051, 2019. See also arXiv:1904.05855.

     


  •  

    Helical Superstructure of Intermediate Filaments

    Lila Bouzar, Martin Michael Müller, René Messina, Bernd Nöding, Sarah Köster, Hervé Mohrbach, Igor M. Kulić

    Abstract     Read more

    Phys. Rev. Lett., 122: 098101, 2019. See also arXiv:1803.04691.

     


  •  

    Vesicle dynamics in confined steady and harmonically modulated Poiseuille flows

    Zakaria Boujja, Chaouqi Misbah, Hamid Ez-Zahraouy, Abdelilah Benyoussef, Thomas John, Christian Wagner, Martin Michael Müller

    Abstract     

    Phys. Rev. E, 98: 043111, 2018. See also arXiv:1810.04500.

     


  •  

    Confining a fluid membrane vesicle of toroidal topology in an adhesive hard sphere

    Lila Bouzar, Ferhat Menas, Martin Michael Müller

    We discuss how the equilibrium shapes of a confined toroidal fluid membrane vesicle change when an adhesion between membrane and confining sphere is taken into account. The case without adhesion was studied in Ref. [1]. Different types of solution were found and assembled in a phase diagram as a function of area and reduced volume of the membrane. Depending on the degree of confinement the vesicle is either free, in contact along a circle (contact-circle solutions) or on a surface (contact-area solutions). All solutions without adhesion are up-down symmetric. When the container is adhesive, the phase diagram is altered and new kinds of solution without up-down symmetry are found. For increasing values of adhesion the region of contact-circle solutions shrinks until it vanishes completely from the phase diagram.

     Reduce     Read more

    IOP Conf. Series: MSE, 186: 012021, 2017.

     


  •  

    Squeezed helical elastica

    Lila Bouzar, Martin Michael Müller, Pierre Gosselin, Igor M. Kulić, Hervé Mohrbach

    We theoretically study the conformations of a helical semi-flexible filament confined to a two-dimensional surface. This squeezed helix exhibits a variety of unexpected shapes resembling circles, waves or spirals depending on the material parameters. We explore the conformation space in detail and show that the shapes can be understood as the mutual elastic interaction of conformational quasi-particles. Our theoretical results are potentially useful to determine the material parameters of such helical filaments in an experimental setting.

     Reduce     Read more

    Eur. Phys. J. E, 39: 114, 2016. See also arXiv:1606.03611.

     


  •  

    How bio-filaments twist membranes

    Julien Fierling, Albert Johner, Igor M. Kulić, Hervé Mohrbach, Martin Michael Müller

    Abstract     

    Soft Matter, 12: 5747, 2016.

     


  •  

    Toroidal membrane vesicles in spherical confinement

    Lila Bouzar, Ferhat Menas, Martin Michael Müller

    Abstract     Read more

    Phys. Rev. E, 92: 032721, 2015. See also arXiv:1509.00765.

     


  •  

    Non-linear buckling and symmetry breaking of a soft elastic sheet sliding on a cylindrical substrate

    Norbert Stoop, Martin Michael Müller

    We consider the axial compression of a thin sheet wrapped around a rigid cylindrical substrate. In contrast to the wrinkling-to-fold transitions exhibited in similar systems, we find that the sheet always buckles into a single symmetric fold, while periodic solutions are unstable. Upon further compression, the solution breaks symmetry and stabilizes into a recumbent fold. Using linear analysis and numerics, we theoretically predict the buckling force and energy as a function of the compressive displacement. We compare our theory to experiments employing cylindrical neoprene sheets and find remarkably good agreement.

     Reduce     Read more

    Int. J. Non-Linear Mech., 75: 115, 2015. See also arXiv:1503.05030.

     


  •  

    Crunching Biofilament Rings

    Julien Fierling, Martin Michael Müller, Hervé Mohrbach, Albert Johner, Igor M. Kulić

    We discuss a curious example for the collective mechanical behavior of coupled non-linear monomer units entrapped in a circular filament. Within a simple model we elucidate how multistability of monomer units and exponentially large degeneracy of the filament's ground state emerge as a collective feature of the closed filament. Surprisingly, increasing the monomer frustration, i.e., the bending prestrain within the circular filament, leads to a conformational softening of the system. The phenomenon, that we term polymorphic crunching, is discussed and applied to a possible scenario for membrane tube deformation by switchable dynamin or FtsZ filaments. We find an important role of cooperative inter-unit interaction for efficient ring induced membrane fission.

     Reduce     Read more

    Europhys. Lett., 107(6): 68002, 2014. See also arXiv:1408.6787.

     


  •  

    Confotronic dynamics of tubular filaments

    Osman Kahraman, Hervé Mohrbach, Martin Michael Müller, Igor M. Kulić

    Abstract     Read more

    Soft Matter, 10(16): pp. 2836-2847, 2014. See also arXiv:1312.3106.

     


  •  

    Whirling skirts and rotating cones

    Jemal Guven, J. A. Hanna, Martin Michael Müller

    Abstract     

    New J. Phys., 15: 113055, 2013. See also arXiv:1306.2619.

     


  •  

    Myotubularin and PtdIns3P remodel the sarcoplasmic reticulum in muscle in vivo

    Leonela Amoasii, Karim Hnia, Gaëtan Chicanne, Andreas Brech, Belinda Simone Cowling, Martin Michael Müller, Yannick Schwab, Pascale Koebel, Arnaud Ferry, Bernard Payrastre, Jocelyn Laporte

    Abstract     

    J. Cell Sci., 126(8): 1806, 2013.

     


  •  

    Dipoles in thin sheets

    Jemal Guven, J. A. Hanna, Osman Kahraman, Martin Michael Müller

    A flat elastic sheet may contain pointlike conical singularities that carry a metrical "charge" of Gaussian curvature. Adding such elementary defects to a sheet allows one to make many shapes, in a manner broadly analogous to the familiar multipole construction in electrostatics. However, here the underlying field theory is non-linear, and superposition of intrinsic defects is non-trivial as it must respect the immersion of the resulting surface in three dimensions. We consider a "charge-neutral" dipole composed of two conical singularities of opposite sign. Unlike the relatively simple electrostatic case, here there are two distinct stable minima and an infinity of unstable equilibria. We determine the shapes of the minima and evaluate their energies in the thin-sheet regime where bending dominates over stretching. Our predictions are in surprisingly good agreement with experiments on paper sheets.

     Reduce     Read more

    Eur. Phys. J. E, 36: 106, 2013. See also arXiv:1212.3262.

     


  •  

    Fluid membrane vesicles in confinement

    Osman Kahraman, Norbert Stoop, Martin Michael Müller

    Abstract     Read more

    New J. Phys., 14: 095021, 2012.

     


  •  

    Petal shapes of sympetaleous flowers: the interplay between growth, geometry and elasticity

    Martine Ben Amar, Martin Michael Müller, Miguel Trejo

    The growth of a thin elastic sheet imposes constraints on its geometry such as its Gaussian curvature KG. In this paper, we construct the shapes of sympetalous bell-shaped flowers with a constant Gaussian curvature. Minimizing the bending energies of both the petal and the veins, we are able to predict quantitatively the global shape of these flowers. We discuss two toy problems where the Gaussian curvature is either negative or positive. In the former case the axisymmetric pseudosphere turns out to mimic the correct shape before edge curling; in the latter case, singularities of the mathematical surface coincide with strong veins. Using a variational minimization of the elastic energy, we find that the optimal number for the veins is either four, five or six, a number which is deceptively close to the statistics on real flowers in nature.

     Reduce     Read more

    New J. Phys., 14: 085014, 2012. Also featured in the Highlights of 2012.

     


  •  

    Morphogenesis of membrane invaginations in spherical confinement

    Osman Kahraman, Norbert Stoop, Martin Michael Müller

    We study the morphology of a fluid membrane in spherical confinement. When the area of the membrane is slightly larger than the area of the outer container, a single axisymmetric invagination is observed. For higher area, self-contact occurs: the invagination breaks symmetry and deforms into an ellipsoid-like shape connected to its outer part via a small slit. For even higher areas, a second invagination forms inside the original invagination. The folding patterns observed could constitute basic building blocks in the morphogenesis of biological tissues and organelles.

     Reduce     Read more

    Europhys. Lett., 97(6): 68008, 2012. See also arXiv:1201.2518.

     


  •  

    Conical instabilities on paper

    Jemal Guven, Martin Michael Müller, Pablo Vázquez-Montejo

    Abstract     Read more

    J. Phys. A: Math. Theor., 45(1): 015203, 2012. See also arXiv:1107.5008.

     


  •  

    Interface-mediated interactions: Entropic forces of curved membranes

    Pierre Gosselin, Hervé Mohrbach, Martin Michael Müller

    Abstract     Read more

    Phys. Rev. E, 83(5): 051921, 2011. See also arXiv:1011.1221.

     


  •  

    Self-Contact and Instabilities in the Anisotropic Growth of Elastic Membranes

    Norbert Stoop, Falk K. Wittel, Martine Ben Amar, Martin Michael Müller, Hans J. Herrmann

    Abstract     Read more

    Phys. Rev. Lett., 105(6): 068101, 2010. See also arXiv:1007.1871.

     


  •  

    Cell Model Approach to Membrane Mediated Protein Interactions

    Martin Michael Müller, Markus Deserno

    Abstract     Read more

    Prog. Theor. Phys. Suppl., 184: pp. 351-363, 2010.

     


  •  

    Hamiltonian formulation of surfaces with constant Gaussian curvature

    Miguel Trejo, Martine Ben Amar, Martin Michael Müller

    Abstract     Read more

    J. Phys. A: Math. Theor., 42(42): 425204, 2009.

     


  •  

    Local Membrane Mechanics of Pore-Spanning Bilayers

    Ingo Mey, Milena Stephan, Eva K. Schmitt, Martin Michael Müller, Martine Ben Amar, Claudia Steinem, Andreas Janshoff

    Abstract     Read more

    J. Am. Chem. Soc., 131(20): pp. 7031-7039, 2009.

     


  •  

    Elasticity Mapping of Pore-Suspending Native Cell Membranes

    Bärbel Lorenz, Ingo Mey, Siegfried Steltenkamp, Tamir Fine, Christina Rommel, Martin Michael Müller, Alexander Maiwald, Joachim Wegener, Claudia Steinem, Andreas Janshoff

    Abstract     Read more

    Small, 5(7): pp. 832-838, 2009.

     


  •  

    Conical Defects in Growing Sheets

    Martin Michael Müller, Martine Ben Amar, Jemal Guven

    A growing or shrinking disc will adopt a conical shape, its intrinsic geometry characterized by a surplus angle φe at the apex. If growth is slow, the cone will find its equilibrium. Whereas this is trivial if φe≤0, the disc can fold into one of a discrete infinite number of states if φe is positive. We construct these states in the regime where bending dominates, determine their energies and how stress is distributed in them. For each state a critical value of φe is identified beyond which the cone touches itself. Before this occurs, all states are stable; the ground state has twofold symmetry.

     Reduce     Read more

    Phys. Rev. Lett., 101(15): 156104, 2008. See also arXiv:0807.1814.

     


  •  

    How paper folds: bending with local constraints

    Jemal Guven, Martin Michael Müller

    Abstract     Read more

    J. Phys. A: Math. Theor., 41(5): 055203, 2008. See also arXiv:0712.0978.

     


  •  

    Contact lines for fluid surface adhesion

    Markus Deserno, Martin Michael Müller, Jemal Guven

    Abstract     Read more

    Phys. Rev. E, 76(1): 011605, 2007. See also cond-mat/0703019.
    Also featured in the Virtual Journal of Biological Physics Research.

     


  •  

    Balancing torques in membrane-mediated interactions: Exact results and numerical illustrations

    Martin Michael Müller, Markus Deserno, Jemal Guven

    Abstract     Read more

    Phys. Rev. E, 76(1): 011921, 2007. See also cond-mat/0702340.
    Also featured in the Virtual Journal of Biological Physics Research.

     


  •  

    Aggregation and vesiculation of membrane proteins by curvature-mediated interactions

    Benedict J. Reynwar, Gregoria Illya, Vagelis A. Harmandaris, Martin Michael Müller, Kurt Kremer, Markus Deserno

    Abstract     Read more

    Nature 447(7143): pp. 461-464, 2007.

     


  •  

    How to determine local elastic properties of lipid bilayer membranes from atomic-force-microscope measurements: A theoretical analysis

    Davood Norouzi, Martin Michael Müller, Markus Deserno

    Abstract     Read more

    Phys. Rev. E, 74(6): 061914, 2006. See also cond-mat/0602662.
    Also featured in the Virtual Journal of Biological Physics Research.

     


  •  

    Mechanical Properties of Pore-Spanning Lipid Bilayers Probed by Atomic Force Microscopy

    Siegfried Steltenkamp, Martin Michael Müller, Markus Deserno, Christian Hennesthal, Claudia Steinem, Andreas Janshoff

    We measure the elastic response of a free-standing lipid membrane to a local indentation by using an atomic force microscope. Starting point is a planar gold-coated alumina substrate with a chemisorbed 3-mercaptopropionic acid monolayer displaying circular pores of very well defined and tunable size, over which bilayers composed of N,N,- dimethyl- N,N,- dioctadecylammonium bromide or 1,2 - dioleoyl - 3 - trimethylammonium - propane chloride were spread. Centrally indenting these 'nanodrums' with an atomic force microscope tip yields force-indentation curves, which we quantitatively analyze by solving the corresponding shape equations of continuum curvature elasticity. Since the measured response depends in a known way on the system geometry (pore size, tip radius) and on material parameters (bending modulus, lateral tension), this opens the possibility to monitor local elastic properties of lipid membranes in a well-controlled setting.

     Reduce     Read more

    Biophys. J., 91(1): pp. 217-226, 2006.

     


  •  

    Interface mediated interactions between particles -- a geometrical approach

    Martin Michael Müller, Markus Deserno, Jemal Guven

    Particles bound to an interface interact because they deform its shape. The stresses that result are fully encoded in the geometry and described by a divergence-free surface stress tensor. This stress tensor can be used to express the force on a particle as a line integral along any conveniently chosen closed contour that surrounds the particle. The resulting expression is exact (i.e., free of any 'smallness' assumptions) and independent of the chosen surface parametrization. Additional surface degrees of freedom, such as vector fields describing lipid tilt, are readily included in this formalism. As an illustration, we derive the exact force for several important surface Hamiltonians in various symmetric two-particle configurations in terms of the midplane geometry; its sign is evident in certain interesting limits. Specializing to the linear regime, where the shape can be analytically determined, these general expressions yield force-distance relations, several of which have originally been derived by using an energy based approach.

     Reduce     Read more

    Phys. Rev. E, 72(6): 061407, 2005. See also cond-mat/0506019.
    Also featured in the Virtual Journal of Biological Physics Research.

     


  •  

    Geometry of surface-mediated interactions

    Martin Michael Müller, Markus Deserno, Jemal Guven

    Abstract     Read more

    Europhys. Lett., 69(3): pp. 482-488, 2005. See also cond-mat/0409043.

     


 

 

2. Books

 

  • New Trends in the Physics and Mechanics of Biological Systems
    Lecture Notes of the Les Houches Summer School, vol. 92 (Oxford University Press, 2011),
    edited by Martine Ben Amar, Alain Goriely, Martin Michael Müller and Leticia Cugliandolo.

    Chapter 9:
    The physics of the cell membrane
    Martin Michael Müller and Martine Ben Amar.

 

 


 

 

3. Theses

  • Theoretical examinations of interface mediated interactions between colloidal particles, diploma thesis (2004).


  • Theoretical studies of fluid membrane mechanics, dissertation (2007).


  • Symmetry breaking in bioelasticity, habilitation thesis (2015).

 

 

 
     

 

     © Martin Michael Müller