2018/12/31 by Stefania Ketzetzi, Joost de Graaf, Rachel P. Doherty +1 · 1 citation
Physics and Astronomy · #cond-mat.soft
paper · pdf · doi:10.1103/physrevlett.124.048002
published as Phys. Rev. Lett. 124, 048002 (2020)
arxiv created 2019/09/09 · arxiv updated 2020/02/05
Catalytic colloidal swimmers that propel due to self-generated fluid flows exhibit strong affinity for surfaces. We here report experimental measurements of significantly different velocities of such microswimmers in the vicinity of substrates made from different materials. We find that velocities scale with the solution contact angle θ on the substrate, which in turn relates to the associated hydrodynamic substrate slip length, as V∝(cosθ+1)-3/2. We show that such dependence can be attributed to osmotic coupling between swimmers and substrate. Our work points out that hydrodynamic slip at the wall, though often unconsidered, can significantly impact the self-propulsion of catalytic swimmers.