Development of novel method to create three-dimensional arrangements of particles using dielectrophoresis in artificially nonuniform electric field

We have developed a novel method to arrange particles three-dimensionally u sing dielectrophoresis in suspension under an artificially nonuniform elect ric field. Particles can be attracted to electric field intensity maxima an d are aligned parallel to an electric field. This alignment is called a "pa rticle chain." As a result, the particle chains are formed only on micro pi llars of metal preformed at selected positions on a flat electrode, because the electric field shows a maximum intensity on tips of the pillars. Two-d imensional arrangements of the one-dimensional chains lead to three-dimensi onal arrangements of the particles. Since uncured polymer is utilized as a suspension medium, the arrangements are stabilized by curing the polymer on healing. Using this method, we succeed in creating three-dimensional arran gements of glass beads with a diameter of 30 mu m in silicone elastomer. In addition, we confirm particle-chain formation of silica spheres with a 5 m u m diameter, which suggests possibility of three-dimensional arrangements of micron-order silica particles and submicron-order particles with a large permittivity such as BaTiO3.