Camphor disk velocity depends on reservoir depth

We investigate the self-propulsion of a camphor disk in a one-dimensional periodic system to study the relationship between the velocity and the water-depth of the aqueous phase. The camphor disk was hypothesized to increase its self-propulsion speed as the water-depth of the system increases due to Marangoni flows. Using an annular ring, we quantified the dynamics exhibited by the camphor disk while varying water-depth: 1mm - 10mm. Our results suggest that the velocity of the camphor disk exhibits a nonmonotonic relationship with water depth – in contrast with some previous studies. We investigate confounding parameters that indicate camphor disk motion is much more complex than we realized. These experiments set the stage to understand the multiparticle dynamics of strongly interacting camphor disks.