OBSERVATION OF ELECTROKINETIC INSTABILITY IN A NEW DOUBLE CROSS-SHAPED MICROCHANNEL

In this paper, numerical and experimental studies are performed to achieve a variety of hybrid types with electrokinetic instability (EKI) effects and to use them in different conductive applications of cross-shaped microchannels. First, this study considers two different types of electrolytes, namely the two electrolytes with the conductivity ratio between 1 and 10, and when the applied DC electric field strength is below the critical value, there will be a hierarchical flow conditions are formed. EKI phenomena are described as coming from the axial velocity and the flow pressure gradient, respectively. In fact, the nature of the electrokinetic instability depends on the relative direction of the conductivity gradient within the microchannel. In addition, a new designed double cross-shaped microchannel structure has also been fabricated and observed operating EKI phenomena. From the experiment, it also can be found that the distance of the upstream length has a profound impact on the mixing of disturbances downstream of the pipeline.