Dependence of dielectrophoretic force on the size of linear erythrocyte aggregates in suspension

For modeling of erythrocyte rouleaux (linear cell aggregates) we develop an approximation procedure for the dipole moment in short cylinders, which contains the case of ellipsoidal bodies as a first approximation, but allows corrections for short cylinders, more representative for such particles. In dependence on the number of erythrocytes in an aggregation, i.e., on different but discrete rouleaux lengths, the dielectrophoretic force is calculated and represented against the frequency of the applied AC field. Predictions are made for frequency regions in the 107–108 Hz range where the magnitude and the direction of dielectrophoretic forces is different for different rouleaux sizes. This property can be used for the detection and spatial separation of rouleaux populations of different length in a microelectronic array.