Two-dimensional hydrodynamic focusing in a simple microfluidic device

Two-dimensional flow focusing in pressure-driven flow is demonstrated in a microfluidic device made of a single cast of a silicon elastomer. A stream injected into the device is shaped to a variety of rectangular profiles. A flow of particles is focused into a thin layer with homogeneous velocity. A blob of dye injected into a microchannel is transported over a long distance with minimal dispersion. The device can be integrated into lab-on-a-chip systems and used as a low-cost flow cytometry chamber.