Sedimentation of a Möbius strip*

Sedimentation of particles is a classical problem of fluid mechanics. While it is well understood that the particle shape uniquely determines its motion, the precise trajectory and orientational dynamics are only known for a limited set of particle shapes. Here we study the sedimentation of a Möbius strip in a viscous fluid under gravity numerically. We approximate the Möbius strip by a rigid collection of spheres, employing the Rotne-Prager-Yamakawa interactions, and solve for its dynamics [1].

We find that the sedimenting Möbius strips follow chiral trajectories, in line with a recent theoretical suggestion [2]. Depending on the initial orientation of the Möbius strip, we report several classes of trajectories and present a proposal for the phase diagram of the system.

[1] D. Palanisamy and W. K. den Otter, J. Chem. Phys. 148, 194112 (2018)

[2] T. A. Witten and H. Diamant, Rep. Prog. Phys. 83 116601 (2020)