Odd Droplets

In chiral systems such as active spinning colloidal matter, time-reversal symmetry-breaking interactions often give rise to a macroscopic continuum description in which the stress tensor contains off-diagonal terms. In fluids, these off-diagonal components lead to so-called "odd-viscous" deformations, in which energy is not dissipated. Odd viscous fluids have been shown to exhibit a rich variety of phenomena, including symmetry-broken flow around translating droplets [1] and asymmetric droplet spreading on superhydrophobic surfaces [2].

Our work investigates the behaviour of droplets in suspension. In particular, we present an analytical solution to the droplet-in-shear problem within the framework of two-dimensional odd Stokes flow, followed by the derivation of a formula for the apparent viscosity of a dilute emulsion. We then explore how chirality can be parametrically varied to tune the bulk rheological properties and control the system’s overall energy dissipation.

[1] Hosaka Y, Komura S, Andelman D. 2021. Phys. Rev. E 104:064613

[2] H. França and M. Jalaal, Odd Droplets: Fluids with Odd Viscosity and Highly Deformable Interfaces, (2025), arXiv:2503.21649 [cond-mat.soft]