RELATIONSHIP OF DIELECTROPHORETIC AND ELECTROROTATIONAL BEHAVIOR EXHIBITED BY POLARIZED PARTICLES

General expressions for the frequency-dependent dielectrophoretic force and electrorotational torque have been derived for electrically polarized particles that either do or do not exhibit dielectric dispersions. Particles with n dielectric dispersions can, at most, exhibit (n + 1) rotational maxima as a function of frequency, and these coincide with regions of maximum frequency-dependence of the dielectrophoretic force. Argand diagrams can be employed to examine the relationships between the dielectrophoretic and electrorotational behaviour of colloidal particles. These results are of relevance to the further understanding of published experimental data and to the application of these two phenomena in the manipulation and characterization of biological cells.