Symmetrically pulsating bubbles swim in an anisotropic fluid by nematodynamics

Kim, Sung-Jo (author), Kos, Žiga (author), Um, Eujin (author), Jeong, Joonwoo (author)

Swimming in low-Reynolds-number fluids requires the breaking of timereversal 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 fluids, nematic liquid crystals (NLC), can make a pulsating spherical bubble swim despite its centrosymmetric shape and timesymmetric motion. The NLC breaks the centrosymmetry by a deformed nematicdirector fieldwithatopologicaldefectaccompanyingthebubble.The nematodynamics renders the nonreciprocity in the pulsation-induced fluid f low. We also report speed enhancement by 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.

• Language: English
• Keywords: hydrodynamics, complex fluids
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication version: Version of Record
• Publication date: 09.02.2024
• Year: 2024
• Number of pages: 8 str.
• Numbering: Vol. 15, art. no. ǂ1220
• PID: 20.500.12556/RUL-155036
• UDC: 532.5
• ISSN on article: 2041-1723
• DOI: 10.1038/s41467-024-45597-1
• COBISS.SI-ID: 189133059
• Publication date in RUL: 15.03.2024

Record is a part of a journal

• Title: Nature communications
• Shortened title: Nat. commun.
• Publisher: Springer Nature
• ISSN: 2041-1723
• COBISS.SI-ID: 2315876

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: hidrodinamika, kompleksne tekočine