Biophysical Society Thematic Meeting | Riga 2026

Active and Responsive Soft Matter: From Biological to Engineered Systems

Poster Abstracts

12-POS Board 12 DYNAMICS OF MACROSCOPIC MAGNETIC SPINNERS Bhagyashri Shinde 1 ; Andrejs Cebers 1 ; 1 University of Latvia, Department of Physics, Riga, Latvia

In class of active matter such as spinners (e.g., membranes with rotating motors), hydrodynamic interactions play an important role and remain not yet fully understood. In this study, we experimentally investigate the dynamics of two macroscopic magnetic spinners immersed in a viscous fluid and driven by an external rotating magnetic field. The spinners are fabricated using 3D printing, with a diameter of 1 cm, and contain embedded cylindrical permanent magnets (height 2 mm, diameter 1 mm). Depending on the driving frequency, the spinner pair exhibits a range of dynamical behaviors, including mutual orbital motion, follower-type motion, and repeated collisions. Orbital trajectories occur within specific frequency regimes, whereas irregular motion and collisions emerge as the driving conditions are varied. For a single frequency value, orbital motion is observed at the initial time; at later times, the spinners start follower-type motion, and during such a change of state of motion, the inter-spinner distance also fluctuates. The Reynolds number of the system (Re ≈ 6 –70) indicates that inertial effects are significant. The resulting dynamics arise from the competition between magnetic, viscous, and inertial forces. Magnetically driven macroscopic spinner systems can serve as accessible model platforms for studying interaction mechanisms relevant to microscopic chiral active fluids including biologycal systems.

44