A Novel Full Hydrodynamic Focusing Design in Flow Cytometer

Hydrodynamic focusing, among various physical mechanisms used in flow cytometers, has proven to be the most effective technique used for aligning sample stream into a single film without rupturing or changing the characteristics of samples. In this paper, a new micro channel design for focusing the sample flow in all directions is presented. Using proposed design, multidimensional hydrodynamic focusing is achieved using conical shaped sheath side channel located around a cylindrical shaped channel containing sample stream. Numerical simulation is performed using COMSOL multi-physics software to explore the effect of several parameters on shape and value of focused stream width. A comparison between the impact of the proposed design and a previous one on the focused stream width is presented to show the efficiency of the model. Furthermore, the effect of multiple hydrodynamic focusing is examined.