Pair Interaction of Catalytical Sphere Dimers in Chemically Active Media

Abstract

We study the pair dynamics of two self-propelled sphere dimers in the chemically active medium in which a cubic autocatalytic chemical reaction takes place. Concentration gradient around the dimer, created by reactions occurring on the catalytic sphere surface and responsible for the self-propulsion, is greatly influenced by the chemical activities of the environment. Consequently, the pair dynamics of two dimers mediated by the concentration field are affected. In the particle-based mesoscopic simulation, we combine molecular dynamics (MD) for potential interactions and reactive multiparticle collision dynamics (RMPC) for solvent flow and bulk reactions. Our results indicate three different configurations between a pair of dimers after the collision, i.e., two possible scenarios of bound dimer pairs and one unbound dimer pair. A phase diagram is sketched as a function of the rate coefficients of the environment reactions. Since the pair interactions are the basic elements of larger scale systems, we believe the results may shed light on the understanding of the collective dynamics.

Stability of a Dumbbell Micro-Swimmer

“…To date, a wide variety of propulsion mechanisms have been proposed to generate motility in micro-swimmers, including magnetic forces, chemical forces, optical forces, bubbles, ultrasound, and fluid oscillation [3,4,5,6,7,8]. Recently, some studies have attempted to establish an assembly of micro-swimmers to generate stronger forces or large-scale mixing [9,10,11,12,13]. The stable assembly of multiple micro-swimmers could be a key technology for future micromachine applications.…”

Modular approach to microswimming

“…However, due to the complex balance between different forces, the multiple components and the more available surfaces compared with swimmers of single active unit, theoretical understanding of the mechanism and performance of modular swimmers is a bit challenging, especially those of dynamic structures. There are several theoretical work on modular swimmers of bound structures [123][124][125][126][127][128][129][130] and few on those with dynamic structures. 71,79,80,131 Until now, to the author's knowledge, no microscopic model based on experimental input for modular swimmers of dynamic structures has been proposed.…”

Selected Papers from 2017 International Conference on Micro/Nanomachines

“…shed light on the understanding of the collective dynamics of synthetic micro/nanomachines, as pair dynamics are the basic elements of the larger scale systems [8]. Ning et al briefly introduced swarming, collective, and adaptive behaviors of interactive micromotors in the view of dynamic interactions between them [1].…”