We have started a new activity on the dynamics of (self-propelled) active colloids interacting with giant vesicles. The activity of Janus colloids due to a chemical reaction occuring on the platinum face of the particle modifies the fluid flow around the colloid and leads to a strong interaction with the lipid vesicle. A variety of interesting phenomena including particle orbital motion around GUVs, and active transport of GUV by the active colloid have been observed.
Figure 1. Time lapse images of a Janus colloid orbiting around a giant vesicle.
Previously, we studied the design principles of the simplest colloidal propeller, an architecture built from four identical spheres that can couple translation with rotation to produce controlled drift motion [1].
Figure 2. The simplest propeller made from an assembly of colloidal spheres. We have shown how the propelling efficiency, i.e the efficiency of transformation of rotation into translation depends on the geometrical characteristics of the aggregate.
[1] Mendoza, C. I.; Marques, C. M.; Thalmann, F. Enhanced shear separation for chiral magnetic colloidal aggregates, Phys. Rev. E, 82, 060401 (2010).