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.