Analytical formulation of electric field and dielectrophoretic force for moving dielectrophoresis using Fourier series

Abstract

Electrokinetics manipulation and separation of living cells employing microfluidic devices require good knowledge of the strength and distribution of electric field in such devices. AC dielectrophoresis is performed by generating non-uniform electric field using microsize electrodes. Among the several applications of dielectrophoretic phenomenon, this present study considers the recently introduced phenomenon of moving dielectrophoresis. An analytical solution using Fourier series is presented for the electric field distribution and dielectrophoretic force generated inside a microchannel. The potential at the upper part of the microchannel has been found by solving the governing equation of the electric potential with specific boundary conditions. The solutions for the electric field and dielectrophoretic force show excellent agreement with the numerical results. Microdevices were fabricated and experiments were carried out with living cells confirming and validating the analytical solutions.

Electromechanical effects on multilayered cells in nonuniform rotating fields

“…Each spectrum is calculated twice: first with the accurate Maxwell stress tensor method and then with the dipole approximation given by Eqs. (3) and (4). If the cell is far from the electrodes (H = 8 μm), higher order terms have a negligible influence on either the force or the torque, to the extent that the corresponding markers and curves appear superimposed in Fig.…”

“…Since the original works, which dealt only with homogeneous spherical particles [2,3], considerable progress has been made both in theoretical calculations with realistic particle models and colloidal suspensions [4][5][6] and in the development of practical applications like biosensors and biomicrofluidic platforms [1].…”

Single living cell manipulation and identification using microsystems technologies

“…Thus, cells that are searched by both size and constant dielectric value will be able to travel through the electrodes, while all the other cells will be retained by the electric field created by the electrode. The cut-off frequencies and the preparation of blood specimens are given in detail in our previous work 24,26 . Figure 1 illustrates four snapshots taken to cells retained by the nDEP, while the marked MDA231 cancer cell is seen to travel the electrode and settle in high electric filed area.…”

“…Selection of the imaging frequency is dependent on the Claussius-Mossotti factor expressed above. In general, a material can be characterized by its unique permittivity signature and conductivity or CP and these parameters are mainly determined by the molecular structure of the material 24 . In fact, the dielectric properties of a material hint on how that material will interact with an applied electromagnetic field.…”

“…As capacitance of the cell membrane varies between cell types, it is possible to have at a given frequency range both pDEP and nDEP within the same blood specimen, thereby enabling the separation of particular cells from the rest of other cell types in the blood sample. Polarizable spherical cell suspended in low-conductivity medium and placed under nonuniform electrical field experiences a DEP force that is given by 24 :…”