Pair Interaction between Two Catalytically Active Colloids

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Priyanka Sharan - , Chair of Physical Chemistry, TUD Dresden University of Technology (Author)
  • Abdallah Daddi-Moussa-Ider - , Max Planck Institute for Dynamics and Self-Organization (Author)
  • Jaime Agudo-Canalejo - , Max Planck Institute for Dynamics and Self-Organization (Author)
  • Ramin Golestanian - , Max Planck Institute for Dynamics and Self-Organization, University of Oxford (Author)
  • Juliane Simmchen - , Chair of Physical Chemistry, TUD Dresden University of Technology, University of Strathclyde (Author)

Abstract

Due to the intrinsically complex non-equilibrium behavior of the constituents of active matter systems, a comprehensive understanding of their collective properties is a challenge that requires systematic bottom–up characterization of the individual components and their interactions. For self-propelled particles, intrinsic complexity stems from the fact that the polar nature of the colloids necessitates that the interactions depend on positions and orientations of the particles, leading to a 2d − 1 dimensional configuration space for each particle, in d dimensions. Moreover, the interactions between such non-equilibrium colloids are generically non-reciprocal, which makes the characterization even more complex. Therefore, derivation of generic rules that enable us to predict the outcomes of individual encounters as well as the ensuing collective behavior will be an important step forward. While significant advances have been made on the theoretical front, such systematic experimental characterizations using simple artificial systems with measurable parameters are scarce. Here, two different contrasting types of colloidal microswimmers are studied, which move in opposite directions and show distinctly different interactions. To facilitate the extraction of parameters, an experimental platform is introduced in which these parameters are confined on a 1D track. Furthermore, a theoretical model for interparticle interactions near a substrate is developed, including both phoretic and hydrodynamic effects, which reproduces their behavior. For subsequent validation, the degrees of freedom are increased to 2D motion and resulting trajectories are predicted, finding remarkable agreement. These results may prove useful in characterizing the overall alignment behavior of interacting self-propelling active swimmer and may find direct applications in guiding the design of active-matter systems involving phoretic and hydrodynamic interactions.

Details

Original languageEnglish
Article number2300817
JournalSmall
Volume19
Issue number36
Publication statusPublished - 6 Sept 2023
Peer-reviewedYes

External IDs

PubMed 37165719

Keywords

Keywords

  • active matter, diffusiophoresis, pair interactions