Size dependence of the propulsion velocity for catalytic Janus-sphere swimmers
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 85:2 (2012)
Authors:
S Ebbens, MH Tu, JR Howse, R Golestanian
Abstract:
The propulsion velocity of active colloids that asymmetrically catalyze a chemical reaction is probed experimentally as a function of their sizes. It is found that over the experimentally accessible range, the velocity decays as a function of size, with a rate that is compatible with an inverse size dependence. A diffusion-reaction model for the concentrations of the fuel and waste molecules that takes into account a two-step process for the asymmetric catalytic activity on the surface of the colloid is shown to predict a similar behavior for colloids at the large size limit, with a saturation for smaller sizes. © 2012 American Physical Society.
