Process (computing)

Engineering

Biology

Human fertilization

Biomedical engineering

Sperm

Materials science

Operating system

Telecommunications

Computer science

Environmental health

Genetics

Physics

Trajectory

Simulation

Anatomy

Astronomy

Infertility

Population

Andrology

Medicine

Chip

Biological system

Pregnancy

Biomicrofluidics

Infertility is a common medical condition encountered by health systems throughout the world. Despite the development of complex in vitro fertilization techniques, only one-third of these procedures are successful. New lab-on-a-chip systems that focus on spermatozoa selection require a better understanding of sperm behavior under ultra-confined conditions in order to improve outcomes. Experimental studies combined with models and simulations allow the evaluation of the efficiency of different lab-on-a-chip devices during the design process. In this work, we provide experimental evidence of the dynamics of sperm interacting with a lateral wall in a shallow chamber. We observe a decrease in average sperm velocity during initial wall interaction and partial recovery after the alignment of the trajectory of the cell. To describe this phenomenon, we propose a simple model for the sperm alignment process with a single free parameter. By incorporating experimental motility characterization into the model, we achieve an accurate description of the average velocity behavior of the sperm population close to walls. These results will contribute to the design of more efficient lab-on-a-chip devices for the treatment of human infertility.

Hitting the wall: Human sperm velocity recovery under ultra-confined conditions