Claus Heussinger

Georg-August-Universität Göttingen, Göttingen, Lower Saxony, Germany

Are you Claus Heussinger?

Claim your profile

Publications (33)119.49 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Modeling approaches of suspended, rod-like particles and recent experimental data have shown that depletion forces display different signatures depending on the orientation of these particles. It has been shown that axial attraction of two rods yields contractile forces of 0.1pN that are independent of the relative axial shift of the two rods. Here, we measured depletion-caused interactions of actin bundles extending the phase space of single pairs of rods to a multi-particle system. In contrast to a filament pair, we found forces up to 3pN . Upon bundle relaxation forces decayed exponentially with a mean decay time of 3.4s . These different dynamics are explained within the frame of a mathematical model by taking pairwise interactions to a multi-filament scale. The macromolecular content employed for our experiments is well below the crowding of cells. Thus, we propose that arising forces can contribute to biological force generation without the need to convert chemical energy into mechanical work.
  • Source
    Poulomi Sadhukhan, Ole Schuman, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: We study the response of F-actin bundles to driving forces through a simple analytical model. We consider two filaments connected by reversibly bound crosslinks and driven by an external force. Two failure modes under load can be defined. \textit{Brittle failure} is observed when crosslinks suddenly and collectively unbind, leading to catastrophic loss of bundle integrity. During \textit{ductile failure}, on the other hand, bundle integrity is maintained, however at the cost of crosslink reorganization and defect formation. We present phase diagrams for the onset of failure, highlighting the importance of the crosslink stiffness for these processes. Crossing the phase boundaries, force-deflection curves display (frequency-dependent) hysteresis loops, reflecting the first-order character of the failure processes. We evidence how the introduction of defects can lead to complex elasto-plastic relaxation processes, once the force is switched off. Depending on, both, the time-scale for defect motion as well as the crosslink stiffness, bundles can remain in a quasi-permanent plastically deformed state for a very long time.
    The European Physical Journal E 05/2014; 37(6). DOI:10.1140/epje/i2014-14058-5 · 2.18 Impact Factor
  • Source
    Matthias Grob, Claus Heussinger, Annette Zippelius
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose a phase diagram for the shear flow of dry granular particles in two dimensions based on simulations and a phenomenological Landau theory for a nonequilibrium first-order phase transition. Our approach incorporates both frictional as well as frictionless particles. The most important feature of the frictional phase diagram is reentrant flow and a critical jamming point at finite stress. In the frictionless limit the regime of reentrance vanishes and the jamming transition is continuous with a critical point at zero stress. The jamming phase diagrams derived from the model agree with the experiments of Bi et al. [Nature (London) 480, 355 (2011)] and brings together previously conflicting numerical results.
    Physical Review E 05/2014; 89(5-1):050201. DOI:10.1103/PhysRevE.89.050201 · 2.33 Impact Factor
  • Source
    Ronny Moebius, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: We use computer simulations to study highly dense systems of granular particles that are driven by oscillating forces. We implement different dissipation mechanisms that are used to extract the injected energy. In particular, the action of a simple local Stokes' drag is compared with non-linear and history-dependent frictional forces that act either between particle pairs or between particles and an external container wall. The Stokes' drag leads to particle motion that is periodic with the driving force, even at high densities around close packing where particles undergo frequent collisions. With the introduction of inter-particle frictional forces this "interacting absorbing state" is destroyed and particles start to diffuse around. By reducing the density of the material we go through another transition to a "non-interacting" absorbing state, where particles independently follow the force-induced oscillations without collisions. In the system with particle-wall frictional interactions this transition has signs of a discontinuous phase transition. It is accompanied by a diverging relaxation time, but not by a vanishing order parameter, which rather jumps to zero at the transition.
    Soft Matter 04/2014; 10(27). DOI:10.1039/c4sm00178h · 4.15 Impact Factor
  • Source
    Ehsan Irani, Pinaki Chaudhuri, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: Using numerical simulations, the rheological response of an athermal assembly of soft particles with tunable attractive interactions is studied in the vicinity of jamming. At small attractions, a fragile solid develops and a finite yield stress is measured. Moreover, the measured flow curves have unstable regimes, which lead to persistent shearbanding. These features are rationalized by establishing a link between the rheology and the inter-particle connectivity, which also provides a minimal model to describe the flow curves.
    Physical Review Letters 12/2013; 112(18). DOI:10.1103/PhysRevLett.112.188303 · 7.73 Impact Factor
  • Source
    Moumita Maiti, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: We study, by computer simulations, the role of different dissipation forces on the rheological properties of highly-dense particle-laden flows. In particular, we are interested in the close-packing limit (jamming) and the question if "universal" observables can be identified that do not depend on the details of the dissipation model. To this end, we define a simplified lubrication force and systematically vary the range $h_c$ of this interaction. For fixed $h_c$ a cross-over is seen from a Newtonian flow regime at small strain rates to inertia-dominated flow at larger strain rates. The same cross-over is observed as a function of the lubrication range $h_c$. At the same time, but only at high densities close to jamming, particle velocity as well as local density distributions are unaffected by changes in the lubrication range -- they are "universal". At densities away from jamming, this universality is lost: short-range lubrication forces lead to pronounced particle clustering, while longer-ranged lubrication does not. These findings highlight the importance of "geometric" packing constraints for particle motion -- independent of the specific dissipation model. With the free volume vanishing at random-close packing, particle motion is more and more constrained by the ever smaller amount of free space. On the other side, macroscopic rheological observables, as well as higher-order correlation functions retain the variability of the underlying dissipation model.
    Physical Review E 11/2013; 89(5-1). DOI:10.1103/PhysRevE.89.052308 · 2.33 Impact Factor
  • Source
    Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: We consider the shear rheology of concentrated suspensions of non-Brownian frictional particles. The key result of our study is the emergence of a pronounced shear-thickening regime, where frictionless particles would normally undergo shear-thinning. We clarify that shear thickening in our simulations is due to enhanced energy dissipation via frictional inter-particle forces. Moreover, we evidence the formation of dynamically correlated particle-clusters of size $\xi$, which contribute to shear thickening via an increase in \emph{viscous} dissipation. A scaling argument gives $\eta\sim \xi^2$, which is in very good agreement with the data.
    Physical Review E 07/2013; 88(5). DOI:10.1103/PhysRevE.88.050201 · 2.33 Impact Factor
  • Source
    Jan Plagge, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: Driven granular systems readily form glassy phases at high particle volume fractions and low driving amplitudes. We use computer simulations of a driven granular glass to evidence a re-entrance melting transition into a fluid state, which, contrary to intuition, occurs by \emph{reducing} the amplitude of the driving. This transition is accompanied by anomalous particle dynamics and super-diffusive behavior on intermediate time-scales. We highlight the special role played by frictional interactions, which help particles to escape their glassy cages. Such an effect is in striking contrast to what friction is expected to do: reduce particle mobility by making them stick.
    Physical Review Letters 10/2012; 110(7). DOI:10.1103/PhysRevLett.110.078001 · 7.73 Impact Factor
  • Source
    Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: The mechanical properties of cells are dominated by the cytoskeleton, an interconnected network of long elastic filaments. The connections between the filaments are provided by crosslinking proteins, which constitute, next to the filaments, the second important mechanical element of the network. An important aspect of cytoskeletal assemblies is their dynamic nature, which allows remodeling in response to external cues. The reversible nature of crosslink binding is an important mechanism that underlies these dynamical processes. Here, we develop a theoretical model that provides insight into how the mechanical properties of cytoskeletal networks may depend on their underlying constituting elements. We incorporate three important ingredients: nonaffine filament deformations in response to network strain; interplay between filament and crosslink mechanical properties; reversible crosslink (un)binding in response to imposed stress. With this we are able to self-consistently calculate the nonlinear modulus of the network as a function of deformation amplitude and crosslink as well as filament stiffnesses. During loading crosslink unbinding processes lead to a relaxation of stress and therefore to a reduction of the network modulus and eventually to network failure, when all crosslink are unbound. This softening due to crosslink unbinding generically competes with an inherent stiffening response, which may either be due to filament or crosslink nonlinear elasticity.
    New Journal of Physics 09/2012; 14(9). DOI:10.1088/1367-2630/14/9/095029 · 3.67 Impact Factor
  • Source
    Richard L C Vink, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: We consider a biopolymer bundle consisting of filaments that are cross-linked together. The cross-links are reversible: they can dynamically bind and unbind adjacent filament pairs as controlled by a binding enthalpy. The bundle is subjected to a bending deformation and the corresponding distribution of cross-links is measured. For a bundle consisting of two filaments, upon increasing the bending amplitude, a first-order transition is observed. The transition is from a state where the filaments are tightly coupled by many bound cross-links, to a state of nearly independent filaments with only a few bound cross-links. For a bundle consisting of more than two filaments, a series of first-order transitions is observed. The transitions are connected with the formation of an interface between regions of low and high cross-link densities. Combining umbrella sampling Monte Carlo simulations with analytical calculations, we present a detailed picture of how the competition between cross-link shearing and filament stretching drives the transitions. We also find that, when the cross-links become soft, collective behavior is not observed: the cross-links then unbind one after the other leading to a smooth decrease of the average cross-link density.
    The Journal of Chemical Physics 01/2012; 136(3):035102. DOI:10.1063/1.3675832 · 3.12 Impact Factor
  • Source
    Bruno Andreotti, Jean-Louis Barrat, Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: The dynamical mechanisms controlling the rheology of dense suspensions close to jamming are investigated numerically, using simplified models for the relevant dissipative forces. We show that the velocity fluctuations control the dissipation rate and therefore the effective viscosity of the suspension. These fluctuations are similar in quasi-static simulations and for finite strain rate calculations with various damping schemes. We conclude that the statistical properties of grain trajectories -- in particular the critical exponent of velocity fluctuations with respect to volume fraction \phi -- only weakly depend on the dissipation mechanism. Rather they are determined by steric effects, which are the main driving forces in the quasistatic simulations. The critical exponent of the suspension viscosity with respect to \phi can then be deduced, and is consistent with experimental data.
    Physical Review Letters 12/2011; 109(10). DOI:10.1103/PhysRevLett.109.105901 · 7.73 Impact Factor
  • Source
    Claus Heussinger, Gregory M Grason
    [Show abstract] [Hide abstract]
    ABSTRACT: Inspired by the complex influence of the globular crosslinking proteins on the formation of biofilament bundles in living organisms, we study and analyze a theoretical model for the structure and thermodynamics of bundles of helical filaments assembled in the presence of crosslinking molecules. The helical structure of filaments, a universal feature of biopolymers such as filamentous actin, is shown to generically frustrate the geometry of crosslinking between the "grooves" of two neighboring filaments. We develop a coarse-grained model to investigate the interplay between the geometry of binding and mechanics of both linker and filament distortion, and we show that crosslinking in parallel bundles of helical filaments generates intrinsic torques, of the type that tend to wind the bundle superhelically about its central axis. Crosslinking mediates a non-linear competition between the preference for bundle twist and the size-dependent mechanical cost of filament bending, which in turn gives rise to feedback between the global twist of self-assembled bundles and their lateral size. Finally, we demonstrate that above a critical density of bound crosslinkers, twisted bundles form with a thermodynamically preferred radius that, in turn, increases with a further increase in crosslinking bonds. We identify the stiffness of crosslinking bonds as a key parameter governing the sensitivity of bundle structure and assembly to the availability and affinity of crosslinkers.
    The Journal of Chemical Physics 07/2011; 135(3):035104. DOI:10.1063/1.3610431 · 3.12 Impact Factor
  • Source
    Claus Heussinger
    [Show abstract] [Hide abstract]
    ABSTRACT: Combining simulations and theory I study the interplay between bundle elastic degrees of freedom and crosslink binding propensity. By slowly driving bundles into a deformed configuration, and depending on the mechanical stiffness of the crosslinking agent, the binding affinity is shown to display a sudden and discontinuous drop. This indicates a cooperative unbinding process that involves the crossing of a free-energy barrier. Choosing the proper crosslinker therefore not only allows us to change the composite elastic properties of the bundle but also the relevant time scales which can be tuned from the single crosslink binding rate to the much longer escape time over the free-energy barrier.
    Physical Review E 05/2011; 83(5 Pt 1):050902. DOI:10.1103/PhysRevE.83.050902 · 2.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: F-actin bundles are prominent cytoskeletal structures in eukaryotes. They provide mechanical stability in stereocilia, microvilli, filopodia, stress fibers and the sperm acrosome. Bundles are typically stabilized by a wide range of specific crosslinking proteins, most of which exhibit off-rates on the order of 1s(-1). Yet F-actin bundles exhibit structural and mechanical integrity on time scales that are orders of magnitude longer. By applying large deformations to reconstituted F-actin bundles using optical tweezers, we provide direct evidence of their differential mechanical response in vitro: bundles exhibit fully reversible, elastic response on short time scales and irreversible, elasto-plastic response on time scales that are long compared to the characteristic crosslink dissociation time. Our measurements show a broad range of characteristic relaxation times for reconstituted F-actin bundles. This can be reconciled by considering that bundle relaxation behavior is also modulated by the number of filaments, crosslinking type and occupation number as well as the consideration of defects due to filament ends.
    Biophysics of Structure and Mechanism 01/2011; 40(1):93-101. DOI:10.1007/s00249-010-0621-z · 2.47 Impact Factor
  • Source
    E M Huisman, C Heussinger, C Storm, G T Barkema
    [Show abstract] [Hide abstract]
    ABSTRACT: Inspired by the ubiquity of composite filamentous networks in nature, we investigate models of biopolymer networks that consist of interconnected floppy and stiff filaments. Numerical simulations carried out in three dimensions allow us to explore the microscopic partitioning of stresses and strains between the stiff and floppy fractions cs and cf and reveal a nontrivial relationship between the mechanical behavior and the relative fraction of stiff polymer: when there are few stiff polymers, nonpercolated stiff "inclusions" are protected from large deformations by an encompassing floppy matrix, while at higher fractions of stiff material the stiff network is independently percolated and dominates the mechanical response.
    Physical Review Letters 09/2010; 105(11):118101. DOI:10.1103/PhysRevLett.105.118101 · 7.73 Impact Factor
  • Source
    Claus Heussinger, Felix Schüller, Erwin Frey
    [Show abstract] [Hide abstract]
    ABSTRACT: Bundles of filamentous polymers are primary structural components of a broad range of cytoskeletal structures, and their mechanical properties play key roles in cellular functions ranging from locomotion to mechanotransduction and fertilization. We give a detailed derivation of a wormlike bundle model as a generic description for the statics and dynamics of polymer bundles consisting of semiflexible polymers interconnected by crosslinking agents. The elastic degrees of freedom include bending as well as twist deformations of the filaments and shear deformation of the crosslinks. We show that a competition between the elastic properties of the filaments and those of the crosslinks leads to renormalized effective bend and twist rigidities that become mode-number dependent. The strength and character of this dependence is found to vary with bundle architecture, such as the arrangement of filaments in the cross section and pretwist. We discuss two paradigmatic cases of bundle architecture, a uniform arrangement of filaments as found in F -actin bundles and a shell-like architecture as characteristic for microtubules. Each architecture is found to have its own universal ratio of maximal to minimal bending rigidity, independent of the specific type of crosslink-induced filament coupling; our predictions are in reasonable agreement with available experimental data for microtubules. Moreover, we analyze the predictions of the wormlike bundle model for experimental observables such as the tangent-tangent correlation function and dynamic response and correlation functions. Finally, we analyze the effect of pretwist (helicity) on the mechanical properties of bundles. We predict that microtubules with different number of protofilaments should have distinct variations in their effective bending rigidity.
    Physical Review E 02/2010; 81(2 Pt 1):021904. DOI:10.1103/PhysRevE.81.021904 · 2.33 Impact Factor
  • Source
    Claus Heussinger, Ludovic Berthier, Jean-Louis Barrat
    [Show abstract] [Hide abstract]
    ABSTRACT: We use computer simulations to study the microscopic dynamics of an athermal assembly of soft particles near the fluid-to-solid, jamming transition. Borrowing tools developed to study dynamic heterogeneity near glass transitions, we discover a number of original signatures of the jamming transition at the particle scale. We observe superdiffusive, spatially heterogeneous, and collective particle motion over a characteristic scale which displays a surprising non-monotonic behavior across the transition. In the solid phase, the dynamics is an intermittent succession of elastic deformations and plastic relaxations, which are both characterized by scale-free spatial correlations and system size dependent dynamic susceptibilities. Our results show that dynamic heterogeneities in dense athermal systems and glass-formers are very different, and shed light on recent experimental reports of `anomalous' dynamical behavior near the jamming transition of granular and colloidal assemblies.
    EPL (Europhysics Letters) 01/2010; 90(2). DOI:10.1209/0295-5075/90/20005 · 2.27 Impact Factor
  • Source
    Claus Heussinger, Pinaki Chaudhuri, Jean-Louis Barrat
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a numerical study of the flow of an assembly of frictionless soft discs at zero temperature, in the vicinity of and slightly above the jamming density. We find that some of the flow properties, such as the fluctuations in the number of contacts or the shear modulus, display a critical like behaviour that is governed by the proximity to the jamming point. Dynamical correlations during a quasistatic deformation, however, are non critical and dominated by system size. At finite strain rates, these dynamical correlations acquire a finite, strain-rate dependent amplitude, that decreases when approaching the jamming point from above. Comment: Manuscript submitted to the themed Issue on granular and jammed materials of Soft Matter
    Soft Matter 01/2010; DOI:10.1039/b927228c · 4.15 Impact Factor
  • Claus Heussinger, Pinaki Chaudhuri, Jean-Louis Barrat
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a numerical study of the flow of an assembly of frictionless grains at zero temperature, in the vicinity of and slightly above the jamming density. We find that some of the flow properties, such as the fluctuations in the number of contacts or the shear modulus, display a critical like behaviour that is governed by the proximity to the jamming point. Dynamical correlations during a quasistatic deformation, however, are non critical and dominated by system size. At finite strain rates, these dynamical correlations acquire a finite, strain-rate dependent amplitude, that decreases when approaching the jamming point from above.
  • Source
    Claus Heussinger, Jean-Louis Barrat
    [Show abstract] [Hide abstract]
    ABSTRACT: We study the rheology of amorphous packings of soft, frictionless particles close to jamming. Implementing a quasistatic simulation method we generate a well-defined ensemble of states that directly samples the system at its yield stress. A continuous jamming transition from a freely flowing state to a yield-stress situation takes place at a well-defined packing fraction, where the scaling laws characteristic of isostatic solids are observed. We propose that long-range correlations observed below the transition are dominated by this isostatic point, while those that are observed above the transition are characteristic of dense, disordered elastic media.
    Physical Review Letters 06/2009; 102(21):218303. DOI:10.1103/PhysRevLett.102.218303 · 7.73 Impact Factor

Publication Stats

646 Citations
119.49 Total Impact Points

Institutions

  • 2011–2015
    • Georg-August-Universität Göttingen
      • Institute for Theoretical Physics
      Göttingen, Lower Saxony, Germany
    • Max Planck Institute for Dynamics and Self-Organization
      Göttingen, Lower Saxony, Germany
  • 2009–2011
    • University of Lyon
      Lyons, Rhône-Alpes, France
  • 2010
    • French National Centre for Scientific Research
      • Laboratoire Charles Coulomb
      Lutetia Parisorum, Île-de-France, France
  • 2006–2010
    • Ludwig-Maximilian-University of Munich
      • • Department of Physics
      • • Arnold Sommerfeld Center for Theoretical Physics (ASC)
      München, Bavaria, Germany