Electrokinetically driven flow control using bare electrodes

This paper presents a novel technique for manipulating fluid flows within microchannels using bare electrodes. The electrodes, with a width of 100 μm, are fabricated using conventional photolithography techniques by etching the bulk flow channel into a glass substrate and then depositing Pt/Cr thin films within this channel. The application of an external voltage to these electrodes produces localized variations in the electrical potential distribution, which in turn induce changes in the velocity and direction of the flow within the microchannel. The effectiveness of the proposed control technique is investigated numerically using computational fluid dynamics simulations and experimentally using a fabricated microchip containing multiple bare electrode-pairs. The results demonstrate that the application of appropriate driving voltages to the bare electrode-pairs enables the microdevice to function as a nozzle, a diffuser, a mixer or a valveless valve.

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