Controlling the diffusion of fullerene-wheeled nanovehicles using hybrid curved substrates

In recent years, several types of nanocars have been developed, demonstrating significant capabilities in molecular transport, bottom-up assembly, and other mechanical tasks. This study proposes an approach for converting the diffusive movement of nanocars into guided motion by adding a gold impurity line to a silver cylindrical substrate in which the width of this gold line, depending on the angle of the arc facing it, varies between 120°, 150°, and 180° from the circumference of the complete cylinder; and the movement of C60, nanotruck, and nanocar on these substrates is investigated. The findings show that gold impurity acts as a repellent barrier, especially at 150°, effectively preventing C60 from entering the silver region even under high-temperature conditions, though the entry eventually occurred at 600 K. Nevertheless, a sufficiently large gold impurity acted as an impermeable obstacle for both the nanocar and nanotruck even at a high temperature of 600 K on 180° and 120°, respectively. The considered geometries effectively restricted deviations from the desired path. Furthermore, the effect of varying impurity line thickness is studied. The results reveal that adjusting the impurity line thickness leads to long-range motion and sufficient diffusion coefficient. The 150° and 180° substrates are optimal for C60 and nanocar across various temperatures, while the nanotruck performs best on the 120° substrate due to its rigid chassis. The presence of impurities within the substrate significantly limits the range of motion in nanomachines by acting as a repellent obstacle or snatching trap.