Design and fabrication of an ac-electro-osmosis micropump with 3D high-aspect-ratio electrodes using only SU-8

Lab-on-a-chip devices require integrated pumping and fluid control in microchannels. A recently developed mechanism that can produce fluid flow is an integrated ac-electro-osmosis micropump. However, like most electrokinetic pumps, ac-electro-osmotic pumps are incapable of handling backpressure as the pumping force mechanism acts on the surface of the fluid rather than the bulk. This paper presents a novel 3D electrode structure designed to overcome this limitation. The electrodes are fabricated using carbon-MEMS technology based on the pyrolysis of the photo-patternable polymer SU-8. The novel ac-electro-osmosis micropump shows an increase in the flow velocity compared to planar electrodes

Increasing the fluid flow velocity in a microchannel using 3D non-metallic electrodes

Handling and manipulating fluid using AC-electroosmosis pumping has recently shown some success. However most AC-electroosmosis pumps studied previously were fabricated using metals such as gold and titanium, which restrict the geometry of electrodes to planar shapes. Previously we have shown that conductive polymers can be used to fabricate 3D planar and high aspect ratio electrodes to drive fluid inside microchannels. This paper presents experimental testing of two designs of AC electroosmotic micropumps for different applied voltages and fluid conductivities