Dielectrophoresis (DEP) and electrorotation (ROT) are two electrokinetic phenomena exploiting nonuniform electric fields to exert a force or torque on biological particles suspended in liquid media. They are widely used in lab-on-chip devices for the manipulation, trapping, separation, and characterization of cells, microorganisms, and other particles. The DEP force and ROT torque depend on the respective polarizabilities of the particle and medium, which in turn depend on their dielectric properties and on the field frequency. In this work, we present a new software, MyDEP, which implements several particle models based on concentric shells with adjustable dielectric properties. This tool enables the study of the variation in DEP and ROT spectra according to different parameters, such as the field frequency and medium conductivity. Such predictions of particle behavior are very useful for choosing appropriate parameters in DEP experiments. The software also enables the study of the homogenized properties of spherical or ellipsoidal multishell particles and provides a database containing published cell properties. Equivalent electrical conductivity and relative permittivity of the cell alone and in suspension can be calculated. The software also offers the ability to create graphs of the evolution of the crossover frequencies with the electric field frequency. These graphs can be directly exported from the software.

This paper describes a comprehensive analysis of the geometrical parameters influencing the sensitivity of a coplanar electrode layout for Electrical Impedance Flow Cytometry. The designs presented in this work have been simulated, fabricated and tested. 3D Finite Element Method was applied to simulate and improve the sensitivity of the coplanar designs for two spacings between electrodes. The proposed model uses conditional expressions to define spatially dependent material properties. The vertical and lateral sensitivities were evaluated for all the designs. The experimental results obtained with polystyrene beads show good agreement with the simulations.Precentering particles with dielectrophoresis allowed to control their position in the microchannel.The optimized designs are envisioned to be used for sizing and characterizing particles from single cells to cell aggregates.