Laminar stream-based microfluidic chip with high efficiency for human sperm motility sorting

A novel laminar stream-based microfluidic chip that can serve as the high efficient technique for human sperm motility sorting through the use of flow cytometry was proposed in this study. Recently, the selection of good sperms in semen plays an important role in the reproductive medicine. However, the traditional sorting methods are normally expensive and time consuming. This modified microfluidic chip provided a new selection, which had advantages of low-cost, high-precision, and disposable. This paper was proposed and tested the interactions between laminar flow and sperm activity. Due to the laminar flow in a different direction, the semen samples were loaded into a curve laminar flow through straight-curve stream and it would offer a y component force for dead sperms to be selected. In addition, the semen samples were loaded into a straight laminar flow and the results showed that most of the proportion of motile sperms with lateral activity can swim across the two fluid boundaries to be sorted. From the results of flow cytometry analysis, the injected semen sample from a straight inlet with the counted percentage of living sperms was 92.68% by the observation in outlet reservoir. Therefore, the microfluidic chip with remarkable sperm motility sorting has the potential for reproductive medicine.