Low sperm motility is one of the top causes of infertility. To help couples conceive, scientists created motorized "spermbots." This mechanism helps poor swimmers reach an egg.

Researchers from the Institute for Integrative Nanosciences at the Leibniz-Institut für Festkörper- und Werkstoffforschung or IFW Dresden wanted to create a new method to help couples conceive. The research team included Mariana Medina-Sánchez, Oliver G. Schmidt, Lukas Schwarz and several colleagues from IFW Dresden.

Using past research on micromotors, the researchers have developed small metal helices that will fit around a sperm's tail. A rotating magnetic field is used to control the helices' movement.

Based on lab tests, the micromotors can be coaxed to attach itself around a sperm and help drive the poor swimmer into an egg before releasing it. The research is still in its early stages and further study is needed before they can conduct clinical tests. However, the debut demonstration already seemed promising. The research team also noted that the metal helices do not harm the sperm cell.

Other existing methods included artificial insemination, which is a simple and straightforward technique wherein a sperm is directly introduced into a woman's uterus using a medical instrument. According to Human Fertilisation & Embryology Authority of the United Kingdom, this inexpensive technique has an average success of less than 30 percent.

A more effective and expensive process is called the in vitro fertilization or IVF. This complicated method involves removal of a woman's eggs from her ovaries using a needle. The retrieved eggs are fertilized in a lab and the embryos will then be transferred back to the uterus. Since each step in the two methods carries risk of failure, the researchers wanted to create a simpler and better option.

"Our results indicate that metal-coated polymer microhelices are suitable for this task due to potent, controllable, and nonharmful 3D motion behavior," the researchers wrote.

"We manage to capture, transport, and release single immotile live sperm cells in fluidic channels that allow mimicking physiological conditions." The research was published in the American Chemical Society's journal Nano Letters.