Active fluid of self-rotating particles

ORAL

Abstract

Suspensions of self-propelled particles, such as bacteria, have received considerable attention. Recently there has been increased interest in suspensions of self-rotating particles, such as Quincke rotors in electric fields and ferromagnetic colloids in alternating magnetic fields. While the individual particles are governed by relatively simple dynamics, the interaction of the particles can result in incredibly complex and interesting phenomena. Experiments show phase separation, macroscopic directed motion, and structure formation (e.g. vortices and asters). Modeling these systems as discrete particles at the micro-scale is computational expensive and limits the study of the rotors collective dynamics. We develop a continuum model for such rotor systems based on derivation for dielectric fluids with internal rotation This model allows us to study properties of the fluid and the existance of active turbulence caused by the rotors. To study the effect of confinement, we include phase parameter to restrict the rotors inside a region with a defined diffuse interface. We then can study the interaction between the rotors and the interface for both a fixed and deformable interface.

*This work was supported by a NSF graduate fellowship and NSF grants 1544196 and 1704996.

Presenters

  • Cody Reeves

    • Applied Math, Northwestern

Authors

  • Cody Reeves

    • Applied Math, Northwestern
  • Igor S Aronson

    • Department of Chemistry, Penn State University
    • Biomedical Engineering, Pennsylvania State University
  • Petia M. Vlahovska

    • Applied Math, Northwestern