Electrokinetically driven active micro-mixers utilizing zeta potential variation induced by field effect

An electrokinetically driven active micro-mixer, which uses localized capacitance effects to induce zeta potential variations along the surface of silica-based microchannels, is presented. It is shown that the mixer is fabricated through etching bulk flow and shielding electrode channels into glass substrates and depositing Au/Cr thin films within the latter to form capacitor electrodes. It was shown that buried shielding electrodes can induce the field effect, resulting in higher variations of zeta potential. It was also demonstrated that the developed microfluidic device permits a high a degree of control over the fluid flow and an efficient mixing effect.