Symmetrically pulsating bubbles swim in an anisotropic fluid by nematodynamics

Symmetrically pulsating bubbles swim in an anisotropic fluid by nematodynamics

Blog Article

Abstract Swimming in low-Reynolds-number fluids requires the breaking of time-reversal symmetry and centrosymmetry.Microswimmers, often with asymmetric shapes, exhibit nonreciprocal motions or exploit nonequilibrium processes to propel.The role of the surrounding fluid has also attracted attention because viscoelastic, non-Newtonian, and anisotropic properties of fluids matter in propulsion efficiency and navigation.Here, we experimentally demonstrate that anisotropic Little White Dress fluids, nematic liquid crystals (NLC), can make a pulsating spherical bubble swim despite its centrosymmetric shape and time-symmetric motion.

The NLC breaks the centrosymmetry by a deformed nematic director field with a topological defect accompanying the bubble.The nematodynamics renders the nonreciprocity in the pulsation-induced fluid flow.We also report speed enhancement by Jeans confinement and the propulsion of another symmetry-broken bubble dressed by a bent disclination.Our experiments and theory propose another possible mechanism of moving bodies in complex fluids by spatiotemporal symmetry breaking.