The possibility of generating high-speed shear-driven flows and their potential application in liquid chromatography

An experimental proof of principle is presented for the possibility to use a shear force field to generate a stable, chromatography enabling fluid now through micrometer and submicrometer channels without the need for a press ure or a voltage gradient. In our setup, we were able to successfully move a color tracer plug at speeds exceeding 2 cm/s through a 0.125-mu m-thick a nd 4-mm-wide channel, without creating a pressure drop or a pressure buildu p. By showing that the speed of microchannel flows can be drastically incre ased by simply switching from one driving farce to another, the presented e xperiments open the road to the development of a new type of chromatography , referred to as shear-driven chromatography, potentially offering unpreced ented separation speeds and resolutions and complying perfectly with the pr esent trend toward the miniaturization and parallelization of analytical se paration equipment.