An electrostatically activated resonant micropump-mixer

An active mixing and pumping strategy is proposed to enhance mixing of two fluids through vortex formation and accumulation. A resonant micropump-mixer is designed and fabricated, where an electrostatically activated plate is placed at or in close vicinity of the interface between the two incoming streams at the junction of a Y- or T-shaped microchannel. Mixing is enhanced by increased interface area between the two fluids during the vortex formation at the tip of the resonant plate. Several packaging techniques are employed so that the two initially segregated streams flow underneath and above the resonant plate. Fabrication of the micropump-mixer is achieved in two steps. Commercial PolyMUMPs process is initially used to fabricate a resonant plate. The resonant plate is then flip-chip bonded into a prefabricated microchannel. The Laser Induced Fluorescence (LIF) technique is used for flow visualization and characterization, where effective mixing and pumping capabilities of the micropump-mixer are demonstrated.