Micro, Nano, and Molecular Systems Theory of Inhomogeneous Condensed Matter Article 2020

Interface-mediated spontaneous symmetry breaking and mutual communication between drops containing chemically active particles

Activedrop

Symmetry breaking and the emergence of self-organized patterns is the hallmark of com- plexity. Here, we demonstrate that a sessile drop, containing titania powder particles with negligible self-propulsion, exhibits a transition to collective motion leading to self-organized flow patterns. This phenomenology emerges through a novel mechanism involving the interplay between the chemical activity of the photocatalytic particles, which induces Mar- angoni stresses at the liquid–liquid interface, and the geometrical confinement provided by the drop. The response of the interface to the chemical activity of the particles is the source of a significantly amplified hydrodynamic flow within the drop, which moves the particles. Furthermore, in ensembles of such active drops long-ranged ordering of the flow patterns within the drops is observed. We show that the ordering is dictated by a chemical com- munication between drops, i.e., an alignment of the flow patterns is induced by the gradients of the chemicals emanating from the active particles, rather than by hydrodynamic interactions.

Author(s): Singh, D. P. and Domínguez, A. and Choudhury, U. and Kottapalli, S. N. and Popescu, M. N. and Dietrich, S. and Fischer, P.
Journal: Nature Communications
Volume: 11
Pages: 2210
Year: 2020
Month: May
Day: 5
Bibtex Type: Article (article)
DOI: 10.1038/s41467-020-15713-y
URL: https://www.nature.com/articles/s41467-020-15713-y
Electronic Archiving: grant_archive

BibTex

@article{2020Singh,
  title = {Interface-mediated spontaneous symmetry breaking and mutual communication between drops containing chemically active particles},
  journal = {Nature Communications},
  abstract = {Symmetry breaking and the emergence of self-organized patterns is the hallmark of com-
  plexity. Here, we demonstrate that a sessile drop, containing titania powder particles with
  negligible self-propulsion, exhibits a transition to collective motion leading to self-organized
  flow patterns. This phenomenology emerges through a novel mechanism involving the
  interplay between the chemical activity of the photocatalytic particles, which induces Mar-
  angoni stresses at the liquid–liquid interface, and the geometrical confinement provided by
  the drop. The response of the interface to the chemical activity of the particles is the source
  of a significantly amplified hydrodynamic flow within the drop, which moves the particles.
  Furthermore, in ensembles of such active drops long-ranged ordering of the flow patterns
  within the drops is observed. We show that the ordering is dictated by a chemical com-
  munication between drops, i.e., an alignment of the flow patterns is induced by the gradients
  of the chemicals emanating from the active particles, rather than by hydrodynamic
  interactions.},
  volume = {11},
  pages = {2210},
  month = may,
  year = {2020},
  slug = {2020singh},
  author = {Singh, D. P. and Domínguez, A. and Choudhury, U. and Kottapalli, S. N. and Popescu, M. N. and Dietrich, S. and Fischer, P.},
  url = {https://www.nature.com/articles/s41467-020-15713-y},
  month_numeric = {5}
}