Holding capacity of a dielectrophoretic barrier for microparticles

A dielectrophoretic barrier is generated with two layers of microelectrode structures so called paired electrode array (PEA) constructing face to face on the top and bottom sides of a microchannel. The barrier is designed to control the movement of particles in combination with a fluid flow. Depending on the relative strength of the DEP force and hydrodynamic force, microparticles or cells carrying by a laminar flow can either penetrate the barrier or be deflected from there. The threshold velocity at which the barrier firstly fails to hold back the particles is a significant parameter to validate the performance of the device. This paper presents an experimental study on the performance of the microfabricated paired electrode array. The electrodes were fabricated with conventional microfabrication techniques. Micron-sized latex beads were used in the investigation. The holding capacity was defined by measuring the threshold velocity of the system. The results provide crucial information for the design of the dielectrophoretic barrier for microparticle manipulation and separation.