Ratchet-Driven Directed Nanoparticle Transport Along a Dipole Chain

Spontaneous generation of directed nanoparticle fluxes near periodic one- or two-dimensional structures in viscous media-the ratchet effect-occurs under specific conditions: particle interaction with a periodic structure, broken symmetry of the system, and weak fluctuations that drive it out of thermodynamic equilibrium. Within the framework of the small potential energy fluctuation model, we investigate the directed motion of a single nanoparticle near a periodic dipole chain. The induced flux was analyzed as a function of three parameters: environmental temperature, fluctuation frequency, and the particle's distance from the chain. Two types of flux dependence on distance were observed. At high temperatures, the flux decreases monotonically with increasing distance. At lower temperatures, the dependence becomes non-monotonic, revealing an optimal nanoparticle position relative to the chain where transport velocity is maximized. Analysis of flux maxima shows that their location is determined primarily by the temperature parameter, while frequency variations affect the flux amplitude but not the position of the maximum. These findings demonstrate that optimal ratchet operation (maximum nanoparticle velocities) can be achieved either by adjusting the particle-periodic structure distance at fixed temperature or, if distance cannot be physically controlled, by varying the temperature.