We demonstrate flow control concepts in a grooved micro-channel using selectively patterned, electroosmotically active surfaces and locally applied electric fields. This framework enables formation of rather complex flow patterns in simple micro-geometries. Ability to vary the electric field magnitude and its polarity also manifests time-dependent flow alterations, which results in flow and species transport control abilities. The results obtained in a single micro-groove constitute the proof of concept for flow and species transport control in an integrated serial micro-fluidic process, where multiple species can be trapped and released in prescribed amounts in a micro-channel with multiple grooves. The groove size determines volume of the entrapped species. In addition, each groove can simultaneously contain one or two species at the same time. The proposed flow and species transport control scheme allows control over the interspecies diffusion and mixing time and length scales by simply adjusting the electric field direction and its magnitude. We envision utilization of flow and species transport in a grooved micro channel, where combinatorial chemistry experiments can be performed using multiple grooves, where each groove can be addressed (filled, emptied or mixed) independently.

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