On the Design and Optimization of Micro-Fluidic Dielectrophoretic Devices: A Dynamic Simulation Study

Abstract

Abstract. Microfabricated interdigitated electrode array is a convenient form of electrode geometry for dielectrophoretic trapping of biological particles within micro-fluidic biochips. We have previously reported experimental results and finite element modeling of the holding forces for both positive and negative dielectrophoretic traps on microfabricated interdigitated electrodes within a microfluidic biochip fabricated in silicon with a 12 µm deep chamber and anodic-bonded glass cover. Based on these prior studies, we present in this paper a dynamic study to investigate the stopping capability of dielectrophoretic devices with limited electrode teeth. Simulation results on the issues of design and optimization of the dielectrophoretic devices are also presented and discussed in detail. Simulation results show that the maximum particle stopping distance in a specific device is very sensitive to the chamber height due to the near-electrode nature of DEP force. The relationship between maximum stopping distance and the applied voltage is presented, and the electrode spacing is found to be important in designing the electrode geometry. The spacing should be no less than the chamber height in order to efficiently capture the particles in a relatively short range at a given applied voltage and flow rate.

Superpositioned dielectrophoresis for enhanced trapping efficiency

“…In configuration B, both the electrodes at the bottom and the top were turned on at a voltage frequency where the particles only obtain a positive dielectrophoretic motion. Both setups correspond to the conventional configurations, which have been used extensively [4][5][6][7]. In the new configuration C, both the electrodes are turned on, but different frequencies are utilized.…”

“…When media with a low conductivity are employed, the pDEP force is strong, and separations may be relatively straightforward. Many strategies have been developed using the pDEP-mode trapping [4][5][6][7]. However, when dealing with living microorganisms, the use of low conductivity buffers leads to a high mortality rate of the microorganisms due to an excessive osmotic stress.…”

“…As a model geometry, the widely used [4][5][6][7] 2-D traps with an array of parallel interdigitated electrodes were chosen. It should be straightforward to fabricate such a system using standard microelectromechanical system (MEMS) technology.…”

Direct Numerical Simulation of Particles in Spatially Varying Electric Fields †

“…A PD-based method in which the induced dipole moments within the particles are computed by accounting for the nearby particles, was developed in Reference [28]. There are several other studies in which only the DEP force lines in the devices were considered and the particle trajectories were estimated without considering the fluid-particle interactions [30,31].…”

Numerical Comparison between Nonisolated and Isolated Metal-Electrode-Based Dielectrophoresis Cell Separation

“…In most electrode-based DEP devices, various structures of coplanar metal electrodes are devised at the bottom of the microchannel to create a nonuniform electric field, e.g., interdigitated, (9,10) castellated, (11,12) curved (13,14) and polynomial. (15) Metal electrodes are made of precious metals usually requiring multilevel deposition processes; in most cases, electrodes are made from chromium/gold, (16) titanium/gold (17) and titanium/platinum.…”