On the design and optimization of micro-fluidic dielectrophoretic devices: a dynamic simulation study.

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 microm 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.