Nucleation of active droplets

• Applicant: Dr. David Zwicker
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 447430501

Phase separation has emerged as an important physical concept for the spatial organization of proteins inside cells. Since cells exist away from thermodynamic equilibrium, the dynamics of such droplets can be very different from those typically observed in soft matter systems. In particular, driven chemical reaction affecting the droplet material can regulate droplet size, count, and growth dynamics. It is likely that also the nucleation dynamics of such active droplets are affected by the reactions. For instance, cells might use chemical reactions to suppress, accelerate or spatially bias nucleation.We here propose a minimal theoretical model of fluctuating active droplets to study nucleation. This model will allow us to examine this inherently stochastic effect both numerically and analytically. Preliminary data indicate that reactions indeed have a significant effect on the homogeneous nucleation rate. Additionally, reactions affect the shape of sessile droplets, which might influence heterogeneous nucleation. Taken together, this project will quantify the nucleation rate and the droplet size distribution after the nucleation stage, which will improve our understanding of biological condensates.

• DFG Programme: Research Grants