This new device was created by a team co-led by Erkan Tüzel, associate professor of physics, biomedical engineering, and computer science at WPI, and Utkan Demirci, professor of radiology and electrical engineering (by courtesy) at Stanford University. The work was funded by two separate but collaborative grants from the National Science Foundation and was published in the most recent issue of Advanced Science, a high-impact, peer-reviewed scientific journal.

The microfluidic device, which can be used in clinics, is dubbed SPARTAN, short for Simple Periodic ARray for Trapping And IsolatioN. It uses a field of three-dimensional posts that create an obstacle course for the swimming sperm cells. The strongest and healthiest sperm get through this array the fastest and then are collected at the outlet to be used in the IVF process.

Traditional sperm-sorting methods used in IVF treatments select sperm that are the fastest swimmers. The SPARTAN device collects sperm that are the fastest and also the healthiest because it culls out those with malformations, such as bent necks or larger heads, which can slow their movement.

"With SPARTAN, we not only get sperm with excellent motility, but also with normal morphology and better DNA integrity, helping families worldwide by reducing the stress of multiple IVF procedures, while potentially increasing pregnancy rates." said Tüzel. "This could increase patients' chances of getting pregnant."

According to the Centers for Disease Control and Prevention, 12 percent of women in the United States between the ages of 15 and 44 deal with infertility issues. In that same age group, 7.3 million American women have used infertility services. And the National Institutes of Health reports that one-third of infertility cases are caused by male reproductive issues, while another third are caused by a combination of male and female reproductive issues or unknown causes.

The SPARTAN device is about 4 millimeters wide and 12 to 16 millimeters long. Sperm are simply injected into one end and the fastest and healthiest are collected on the opposite end for immediate use in in vitro fertilization. The device also prevents the type of damage to cells that can occur with traditional sorting methods, such as those using high-force centrifuges. Because SPARTAN can be used in the fertility clinic, sperm do not need to be frozen and shipped to a lab for processing; the in-clinic sorting procedure takes between 5 and 30 minutes.