title: Dielectrophoresis of nanocolloids: a molecular dynamics study.
abstract: Dielectrophoresis (DEP), the motion of polarizable particles in non-uniform electric fields, has become an important tool for the transport, separation, and characterization of microparticles in biomedical and nanoelectronics research. In this article we present, to our knowledge, the first molecular dynamics simulations of DEP of nanometer-sized colloidal particles. We introduce a simplified model for a polarizable nanoparticle, consisting of a large charged macroion and oppositely charged microions, in an explicit solvent. The model is then used to study DEP motion of the particle at different combinations of temperature and electric field strength. In accord with linear response theory, the particle drift velocities are shown to be proportional to the DEP force. Analysis of the colloid DEP mobility shows a clear time dependence, demonstrating the variation of friction under non-equilibrium. The time dependence of the mobility further results in an apparent weak variation of the DEP displacements with temperature.
authors.affiliation: Biological Physics and Soft Matter Group, Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology, Finland. emppu.salonen@hut.fi
authors.forename: E
authors.initials: E
authors.lastname: Salonen
authors.forename: E
authors.initials: E
authors.lastname: Terama
authors.forename: I
authors.initials: I
authors.lastname: Vattulainen
authors.forename: M
authors.initials: M
authors.lastname: Karttunen
mesh_terms: D003102:Colloids / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D004586:Electrophoresis / Q000379:methods*; D008956:Models, Chemical; D009038:Motion; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects*; D011829:Radiation Dosage
chemical_list: D003102:Colloids