title: Colloidal motility and pattern formation under rectified diffusiophoresis.
abstract: In this Letter, we characterize experimentally the diffusiophoretic motion of colloids and lambda-DNA toward higher concentration of solutes, using microfluidic technology to build spatially and temporally controlled concentration gradients. We then demonstrate that segregation and spatial patterning of the particles can be achieved from temporal variations of the solute concentration profile. This segregation takes the form of a strong trapping potential, stemming from an osmotically induced rectification mechanism of the solute time-dependent variations. Depending on the spatial and temporal symmetry of the solute signal, localization patterns with various shapes can be achieved. These results highlight the role of solute contrasts in out-of-equilibrium processes occurring in soft matter.
authors.affiliation: LPMCN, Université Lyon 1 and CNRS, UMR 5586, F-69622 Villeurbanne, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Palacci
authors.forename: Benjamin
authors.initials: B
authors.lastname: Abécassis
authors.forename: Cécile
authors.initials: C
authors.lastname: Cottin-Bizonne
authors.forename: Christophe
authors.initials: C
authors.lastname: Ybert
authors.forename: Lydéric
authors.initials: L
authors.lastname: Bocquet