Attitude and positioning control of elliptical particle using induced-charge electrophoresis for reading information

Abstract

Attitude and positioning control of particles are important for reading information precisely from particles in a flow channel because the difference in the attitudes and positioning of particles results in reading a different signal and causes an error. We intend to control the attitude of elliptical conductive particles by induced-charge electrophoresis (ICEP) and numerically examine the performance of the attitude control through ICEP. By the multiphysics coupled simulation technique between fluidics and electrostatics based on the boundary element method along with the thin-double-layer approximation, we precisely consider the boundary effects on ICEP and dielectrophoresis (DEP) in a converging channel. By the analysis, for single particle systems in a channel, we find that, preferably, the electric field applied parallel to the channel not only turns the particle in the direction of the channel by the ICEP torque but also moves the particle to the center of the channel by the repulsion resulting from a wall–particle interaction due to ICEP. By this analysis, we can greatly contribute to developments in studies on biosensors.