Electrostatic manipulation of particle

We have been investigating an electrostatic manipulation of a small particle, such as toner and carrier particles. A manipulator consisted of two parallel pin electrodes. When voltage was applied between the electrodes, electrophoresis force generated in nonuniform electrostatic field was applied to the particle near the tip of the electrode. The particle was captured by the application of the voltage and released from the manipulator by turning off the voltage application. It was possible to manipulate not only insulative but also conductive particles. However, if the particle was charged, Coulomb force and adhesion force prevented to release the particle when the voltage was turned off. This condition was apt to take place for small particles, less than 200 μm in diameter. The third electrode was introduced near the dipole electrodes to blow off the particle by the ionic wind and the validity of this system was demonstrated. An uneven electrode system without the additional separation electrode was also developed to release the attached particle independently of the position of the manipulator. Three-dimensional calculation was conducted by the Finite Difference Method and compared to the measured force.