In reality, colloidal particles often possess an arbitrary inhomogeneity profile. We present a first-principles approach to dielectrophoresis of such an inhomogeneous colloidal particle under an inhomogeneous field of an oscillating electric dipole moment. For numerical simulations, we treat the inhomogeneous particle as a specific graded one with a physically motivated dielectric model and con...

Although separation of polymers based on the combination of dielectrophoretic trapping and electrophoretic forces has already been proposed 15 years ago [1], the experimental realization has only recently been demonstrated [2]. Here, we address the fast separation of biotechnologically relevant DNA by utilizing electrodeless dielectrophoresis in a simple, structured microfluidic chip. In additi...

Microfludic devices with integrated electrical detection will enable fast, low-cost or portable sensing and processing of biological and chemical samples. As an inherent property of microfabrication, microelectrical impedance spectroscopy detectors can take advantage of AC electrokinetics for particle manipulation, leading to enhanced sensitivity. Preliminary experiments on particle detection w...

Liquid dielectrophoresis is exploited to initiate rapid, transient flow of aqueous liquids along co-planar electrodes patterned on insulating substrates. The flow induced by the non-uniform electric field leads to a new electrostatic equilibrium. A reduced-order model predicts the transient motion of the rivulet. When the field is removed, capillary instability breaks up the rivulet into regula...

A theoretical study of the dielectrophoretic ~DEP! spectrum of a pair of touching colloidal particles or biological cells in a host fluid under the application of a nonuniform alternating current ~ac! electric field is presented. The main objective of this work is to investigate the correlation effects due to the presence of mutual polarization on the DEP spectrum. In particular, we employ the ...