title: Entropic electrokinetics: recirculation, particle separation, and negative mobility.
abstract: We show that when particles are suspended in an electrolyte confined between corrugated charged surfaces, electrokinetic flows lead to a new set of phenomena such as particle separation, mixing for low-Reynolds micro- and nanometric devices, and negative mobility. Our analysis shows that such phenomena arise, for incompressible fluids, due to the interplay between the electrostatic double layer and the corrugated geometrical confinement and that they are magnified when the width of the channel is comparable to the Debye length. Our characterization allows us to understand the physical origin of such phenomena, therefore, shedding light on their possible relevance in a wide variety of situations ranging from nano- and microfluidic devices to biological systems.
authors.affiliation: Department de Fisica Fonamental, Universitat de Barcelona, Carrer Martí i Franqués, 08028-Barcelona, Spain.
authors.forename: Paolo
authors.initials: P
authors.lastname: Malgaretti
authors.affiliation: Department de Fisica Fonamental, Universitat de Barcelona, Carrer Martí i Franqués, 08028-Barcelona, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Pagonabarraga
authors.affiliation: Department de Fisica Fonamental, Universitat de Barcelona, Carrer Martí i Franqués, 08028-Barcelona, Spain and Department of Chemistry, Imperial College London, SW7 2AZ London, United Kingdom.
authors.forename: J Miguel
authors.initials: JM
authors.lastname: Rubi
mesh_terms: D004573:Electrolytes / Q000737:chemistry*; D019277:Entropy; D007473:Ion Channels / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D046210:Microfluidic Analytical Techniques; D008956:Models, Chemical; D055672:Static Electricity
chemical_list: D004573:Electrolytes; D007473:Ion Channels; D007477:Ions