Department Biological Physics
Frank Jülicher

for the Physics of Complex Systems
Nöthnitzer Straße 38
01187 Dresden

Tel. +49 351 871-1202
Fax. +49 351 871-1299
Curriculum Vitae
List of Publications
Research Interests

Theory of Biological Systems and Processes

The main focus of our research are theoretical approaches to understand dynamic processes in cells and tissues. Work on active cellular processes includes the study of cellular oscillations, cellular signaling and the cytoskeletal dynamics during cell division and cell motility. We furthermore study the biophysical basis of hearing. Finally, we investigate the biophysical properties and dynamics of tissues and epithelia. Based on the properties of individual cells and of cellular signaling systems, we are interested in the dynamics of developmental processes, for example wing development in the fruit fly.

Research topics include:

Active cellular processes
Cellular oscillations
Swimming of microorganisms
Cell locomotion

Physics of the cytoskeleton and of motor proteins
Active gels and fluids
Collective behaviors of motor proteins
Self-organization phenomena in the cytoskeleton

Physics of Cell Division

Tissues and developmental processes
Cellular packings in epithelia
Cellular rearrangements during growth and development
Morphogen signaling and morphogen gradient formation

Biophysics of hearing
Active mechanics of hair cells
Cochlear waves
Signal amplification by nonlinear oscillators

Research Highlights
Hydrodynamic Theory of Active Matter
F. Jülicher, S. W. Grill and G. Salbreux
Rep. Prog. Phys. 81, 076601 (2018)
PDF (2,5 MB)]
Critical Point in Self-Organized Tissue Growth
D. Aguilar-Hidalgo, S. Werner, O. Wartlick, M. Gonzalez-Gaitan, B. M. Friedrich
and F. Jülicher
Phys. Rev. Lett. 120, 198102 (2018)
PDF (2,9 MB)]
Chemical event chain model of coupled genetic oscillators
D. J. Jörg, L. G. Morelli and F. Jülicher
Phys. Rev. E. 97, 032409 (2018)
PDF (1,2 MB)]
Generic Properties of Stochastic Entropy Production

We present a stochastic differential equation for the time evolution of entropy in Langevin processes. We show that entropy fluctuation exhibit universal properties which are a conse-quence of a simple stochastic time transformation.

S. Pigolotti, I. Neri, É. Roldán and F. Jülicher
Phys. Rev. Lett. 119, 140601 (2017)
PDF (651 kB)]
Mechanics of Active Surfaces

Active matter is driven at molecular scales away from thermodynamic equilibrium by energy transfusing processes. The theory of bulk active matter is well developed and reveals uncon-ventional material properties and the emergence of active stresses. Here we study active matter that is organised in thin films or sheets that are embedded in three dimensional space. We derive a general theory of the mechanics and the material properties of active surfaces that can account for the interplay of active mechanics and surface deformations.

G. Salbreux and F. Jülicher
Phys. Rev. E 96, 032404 (2017)
PDF (1 MB)]
Droplet Ripening in Concentration Gradients

We investigate the collective dynamics of droplets that undergo ripening in a spatially inho-mogeneous system. As a result of a supersaturation gradient we find novel and unexpected behaviours that differ fundamentally from the classical ripening scenarios. A key results is that droplets can narrow their size distribution and reach almost equal sizes. As a conse-quence of equal droplet sizes, ripening transiently arrests.

C. Weber, C. F. Lee and F. Jülicher
New J. Phys. 19, 053021 (2017)
PDF (676 kB)]
Controlling Contractile Instabilities in the Actomyosin Cortex

The cell cortex is a thin layer of an active material with contractile properties. Here we discuss pulsating contractile patterns that emerge from an interplay of a contractile insta-bility in the material and regulation of contractility by a chemical oscillatory process. Our work shows how cells can control a physical instability using biochemical regulation in or-der to achieve stable function of contractile systems.

M. Nishikawa, S. R. Naganathan, F. Jülicher and S. W. Grill
eLife 2017;10.7554/eLife.19595 (2017)
PDF (9,5 MB)]
Triangles Bridge the Scales: Quantifying Cellular Contributions to Tissue Deformation

We present an exact decomposition of tissue deformations in contributions that stem from a distinct cellular processes. This decomposition is based on a triangulation of the poly-gonal cellular network. It allows us to quantify how cell shape changes, cell neighbour exchanges, cell divisions and extrusions contribute to anisotropic tissue deformations in the developing fly wing.

M. Merkel, R. Etournay, M. Popovic, G. Salbreux ,S. Eaton and F. Jülicher
Phys. Rev. E. 95, 032401 (2017)
PDF (4 MB)]
Active Dynamics of Tissue Shear Flow

Tissues are active soft materials that are assemblies of large numbers of individual cells that adhere to each other. The material properties of a tissue results from cell material properties together with the dynamic rules of cell-cell attachments and cell neighbour exchanges. Here, we introduce a continuum theory for tissue dynamics that applies on large scales but that takes into account cellular processes such as cell shape changes or the rate of cell neighbour exchanges. We show that memory effects can give rise to uncon-ventional and novel rheological properties.

M. Popovic, A. Nandi, M. Merkel, R. Etournay, S. Eaton, F. Jülicher and G. Salbreux
New J. Phys. 19, 033006 (2017)
PDF (1,6 MB)]
Statistics of Infima and Stopping Times of Entropy Production and Applications to Active Molecular Processes

We derive general properties of entropy production fluctuations in nonequilibrium mesoscopic systems. In particular, we show that the minimal values of produced entropy are stochastic variables with a statistic that obeys general bounds. The average infimum of entropy production is bounded from below by - k_B. Our results can be applied to active molecular processes such as the stepping motion of molecular motors.

I. Neri, É. Roldán and F. Jülicher
Phys. Rev X, 7, 011019 (2017)
PDF (1,4 MB)]
Growth and Division of Active Droplets Provides a Model for Protocells

We show that liquid droplets that are driven away from thermodynamic equilibrium by chemical reactions can undergo cycles of growth and division reminiscent of living cells. We propose such active droplets as simple models for prebiotic protocells. Our work shows that protocells could have been able to propagate and divide without having established membranes.

D. Zwicker, R. Seyboldt, C. A. Weber, A. A. Hyman and F. Jülicher
Nature Physics 13, 408 (2017)
PDF (981 kB)]
Highlights 2016
Highlights 2015
Highlights 2014
Highlights 2013
Highlights 2012
Highlights 2011
Highlights 2010
Highlights 2009
Highlights 2008
Highlights 2007
Last updated: June 14, 2018