General expressions for dielectrophoretic force and electrorotational torque derived using the Maxwell stress tensor method

We explore the application of the Maxwell stress tensor (MST) method to dielectrophoresis (DEP) and electrorotation (ROT) studies. By integrating the Maxwell stress tensor over the surface of a dielectric particle, we derive the general expressions for DEP force and ROT torque generated by electrical fields of arbitrary configuration. This is the first time that such complete expressions are derived from first principles using the MST formalism. The results are compared and shown to be in agreement with those obtained from the effective moment approach. The origin of DEP forces in a harmonic field is discussed in terms of field magnitude and phase distributions. (C) 1997 Elsevier Science B.V.