Catalytic Asymmetry Dictating Emergent Dynamics and Self-Assembly in Janus Dimer Pairs

An understanding of motor pairing
dynamics as governed by two-body
interactions underpins the elucidation of their self-assembly and
collective behavior. In this work, we employ a hybrid molecular dynamics-multiparticle
collision dynamics (MD-MPC) approach to develop a particle-based model
of a Janus-sphere dimer motor together with its surrounding complex,
multicomponent active fluid environment. The conformational dynamics
of the motor pair, in the presence of concentration coupling arising
from various catalytic distributions, is microscopically investigated.
Multiple conformational states were observed, including 8 stable and
13 long-lived metastable configurations. These motor pairs exhibited
a variety of modes of motion, including cyclic, rotational, helical,
and oscillatory dynamics. By analyzing diffusiophoretic forces arising
from chemical concentration gradients, we elucidate the physical mechanisms
underlying these diverse configurations. The systematic characterization
of motor-pair dynamics and conformational states provides a mechanistic
foundation, thereby enabling the extension of this framework to studies
of higher-order self-assembly and collective phenomena in chemically
active, many-body systems.