Large Active Polymers and Membranes

Gerhard Gompper
Forschungszentrum Jülich, Germany

Abstract:
Active matter exhibits a wealth of emerging non-equilibrium behaviors [1]. A paradigmatic example is the interior of cells, where active components, such as the cytoskeleton, are responsible for its structural organization and the dynamics of the various components. Of particular interest are the properties of polymers and filaments [2]. The intimate coupling of thermal and active noise, hydrodynamic interactions, and polymer conformations implies the emergence of novel structural and dynamical features.

Recent theoretical and simulation developments and results for the structural and dynamical properties of polymers and filaments exposed to activity will be reviewed. Different propulsion mechanisms are considered, such as chains of active Brownian particles [3], or filaments propelled along their contours [4,5,6]. This leads to interesting single-particle behavior, such as a softening of a semiflexible filament of active Brownian particles at intermediate levels of activity [3], or a sperm-like beating motion of a filament pushing a load. At high polymer densities in two dimensions, collective dynamics characterized by active turbulence is observed [5]. Closed polymer rings (in two-dimensions) can be considered as a model of cell membranes. Here, active components lead to enhanced fluctuations [7] and cell motility [8].

References:
[1] J. Elgeti, R.G. Winkler, and G. Gompper, Rep. Prog. Phys. 78, 056601 (2015).
[2] R.G. Winkler, J. Elgeti, and G. Gompper, J. Phys. Soc. Japan 86, 101014 (2017).
[3] T. Eisenstecken, G. Gompper, and R.G. Winkler, J. Chem. Phys. 146, 154903 (2017).
[4] R.E. Isele-Holder, J. Elgeti, and G. Gompper, Soft Matter 11, 7181 (2015).
[5] Ö. Duman, R.E. Isele-Holder, J. Elgeti, and G. Gompper, Soft Matter 14, 4483 (2018).
[6] A. Ravichandran, Ö. Duman, M. Hoore, G. Saggiarato, G.A. Vliegenthart, T. Auth, and G. Gompper, eLife 8, e39694 (2019).
[7] S.M. Mousavi, G. Gompper, and R.G. Winkler, J. Chem. Phys. 150, 064913 (2019).
[8] C. Abaurrea Velasco, S.D. Ghahnaviyeh, H.N. Pishkenari, T. Auth, and G. Gompper, Soft Matter 13, 5865 (2017).