title: Electrokinetic behavior of two touching inhomogeneous biological cells and colloidal particles: effects of multipolar interactions.
abstract: We present a theory to investigate electrokinetic behavior, namely, electrorotation and dielectrophoresis under alternating current (ac) applied fields for a pair of touching inhomogeneous colloidal particles and biological cells. These inhomogeneous particles are treated as graded ones with physically motivated model dielectric and conductivity profiles. The mutual polarization interaction between the particles yields a change in their respective dipole moments, and hence in the ac electrokinetic spectra. The multipolar interactions between polarized particles are accurately captured by the multiple images method. In the point-dipole limit, our theory reproduces the known results. We find that the multipolar interactions as well as the spatial fluctuations inside the particles can affect the ac electrokinetic spectra significantly.
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong and Biophysics and Statistical Mechanics Group, Helsinki University of Technology, P O Box 9203, Helsinki FIN-02015 HUT, Finland.
authors.forename: J P
authors.initials: JP
authors.lastname: Huang
authors.forename: Mikko
authors.initials: M
authors.lastname: Karttunen
authors.forename: K W
authors.initials: KW
authors.lastname: Yu
authors.forename: L
authors.initials: L
authors.lastname: Dong
authors.forename: G Q
authors.initials: GQ
authors.lastname: Gu
mesh_terms: D001703:Biophysics / Q000379:methods*; D004586:Electrophoresis; D004594:Electrophysiology; D007700:Kinetics