Electrode-rail dielectrophoretic assembly effect: formation of single curvilinear particle-chains on spiral microelectrodes

Abstract

An electrode-rail dielectrophoretic (DEP) assembly effect for microparticle pearl-chain formation is reported. Under this assembly effect, single curvilinear particle chains are formed along spiral strip electrodes in a dielectrophoretic microfluidic device actuated by alternating signals. Moreover, the snaking traveling movement of the entire individual curving pearl chain along the spiral electrode is also observed. The formation of single curvilinear pearl chain could be mainly interpreted by the specific distribution of the electric field above the spiral microelectrode array. Further, the inter-attracting DEP force between neighboring particles in pearl chains is generated when the originally uniform electric field is strongly perturbed due to the existence of the particles themselves. The entire individual pearl chain’s movement along the spiral strip electrode could be rationalized by the non-ignorable ohmic resistance distribution along the strip electrodes, which leads to the nonuniformity of field strength and DEP force along the spiral elongation direction.