3D sheath flow using hydrodynamic position control of the sample flow

3D sheath flow was realized using hydrodynamic position control of the sample flow. The symmetric microgrooves formed on the channel walls were utilized to generate local directional streams. The sample introduced into the grooved area was shifted to the center region of the microchannel, and 3D sheath flow was formed passively. Using CFD (computational fluid dynamics) simulation, the flow shift area was designed to achieve 3D sheath flow no longer than 500 νm in channel length. Sample flow shift behavior was observed by using a confocal microscope. Since the structure of the inlets was very simple, it was possible to fabricate an in-plane multi-sample 3D sheath flow device. As a demonstration, a two-sample 3D sheath flow device was fabricated. The separated two-sample 3D sheath flow configuration was clearly observed.