Design and analysis of extruded quadrupolar dielectrophoretic traps

We present the design and experimental analysis of a dielectrophoretic trap composed of four microfabricated gold posts excited in a quadrupolar fashion. Using quantitative modeling tools, we have designed these extruded traps to attain strong holding against flow while being constrained by a set of system parameters. The extruded geometry consists of cylindrical electrodes in a trapezoidal arrangement and substrate-interconnect shunts. The traps can be individually electrically switched, are easily arrayable, and are amenable to batch fabrication. We have verified the predicted performance of the extruded traps by measuring holding of beads against flows and comparing to the model predictions. The results demonstrate that extruded quadrupolar traps exhibit strong particle confinement and that the modeling tools can be used for a priori design of dielectrophoresis-based single-particle traps. (C) 2002 Elsevier Science B.V. All rights reserved.