A German research team engineered a tiny robotic tail for sperm.
Each year, millions of Americans will struggle to conceive a child. The causes of infertility issues are manifold, but one of the major sources of infertility in men is due to something called low sperm motility, meaning the sperm struggles to swim toward the egg. There are, of course, procedures for those with fertility issues, although the two most common options—in vitro fertilization and artificial insemination—have relatively low levels of success.
So in an effort to provide a more effective solution to infertility, particularly infertility resulting from low sperm motility, a team of researchers at German Institute for Integrative Nanosciences has harnessed the awesome power of magnetic fields to create a tiny robotic tail for struggling sperm.
In a study recently published in Nano Letters, the team unveiled its spermbot, which is essentially a small metal coil (called a ferromagnetic microtube) large enough to fit around the tail of a sperm, but not large enough to slip over the head. The research team used a rotating magnetic field to guide the microtube to a sperm, making use of the sperm's tail to propel the microtube encased sperm toward an egg. When the sperm reaches the egg, it begins the fertilization process and as it enters the egg, its robotic tail simply slips off.
While this is a pretty awesome solution to infertility, the idea for the spermbot has been around for a few years. The team was building on initial successes experienced in 2013 by another team from the institute, making small but important alterations to the motor's design, most notably the change from a more classic tube to the helix shape seen above.
According to the team, this infertility treatment has several advantages not found in currently existing alternatives. It is relatively uncomplicated, especially when compared with in vitro fertilization which involves extracting an egg, inseminating it outside the body and then reinjecting it into the uterus. Moreover, the spermbot could be deployed at a fraction of the cost of alternative treatments, which can cost upwards of $10,000 per cycle for in vitro fertilizations and over $1000 for artificial inseminations.
That being said, the spermbot was only tested out in a laboratory setting using bovine sperm, which share many characteristics with human sperm. Deploying it in humans would involve a whole host of challenges not found in a petri dish, such as the complications of using a magnetic field to guide the sperm without being able to see the motor's movements while in the body. Moreover, while the magnetic fields used in the spermbot do not harm the body's living tissue and the robotic tales do minimal damage to the sperm themselves, the research team still needs to see how a woman's immune system would react to the presence of these foreign bodies.
"Unfortunately, similar to many promising applications in biomedical engineering, it appears to be still a long way from artificially motorized sperm delivery to actual…fertilization," the team wrote in its study. "Still, this work serves to demonstrate a new approach to artificial reproduction that is, in principle, also applicable in vivo and would thus allow to avoid all complications that arise from [in vitro fertilization]."