Analysis of sperm cell motion in high viscosity Newtonian and non-Newtonian fluids using a microfluidic channel

The migration of sperm cells in a female reproductive tract is responsible for the successful fertilization of the female egg. In this research work, the effect of the surrounding fluids on the motion of sperm cells has been studied using a microfluidic channel. To analyze the motility of sperm, primary motility parameters such as velocity, beat frequency, amplitude, and derived parameters such as linearity, straightness, and wobble have been measured. The results indicate that sperms possess higher progressive motility in non-Newtonian fluids compared to Newtonian fluids in the same viscosity range. The motion of the sperm shows an inverse relationship between the amplitude of the head trajectory and the beat frequency of the flagella. Numerical studies were performed to measure the drag force on these sperm. The trajectories of the flagella, forces acting on sperm, power generated, pulling power, and efficiency of the sperm motion through the fluid medium have been investigated and a relationship between the force and rotation of the flagella has been established. The results show that the flagella also change their shape based on the properties of the surrounding fluid. This study aims to improve our understanding of issues related to infertility diagnosis and help design in-vitro experiments required for sperm separation.