A nano-robot motor that wraps around sperm in order to drive it towards an egg could provide hope for men with low fertility rates.
One of the most common causes of infertility in men stems from sperm that are able to fertilise a human egg but are unable to swim to their intended destination.
Researchers at the Institute for Integrative Nanosciences at IFW Dresden in Germany have developed nanomotors which wrap around sperm tails in order to give them back their mobility and direct them towards the egg.
The team said they wanted to improve upon current methods of aiding fertility. While artificial insemination is a relatively inexpensive process, it has a success rate lower than 30 per cent; the other alternative, in vitro fertilisation, is more successful but comes at a high cost and complexity.
They constructed tiny metal helices just large enough to fit around the tail of a sperm, the movements of which could be controlled by a rotating magnetic field.
Lab testing showed that the motors can be directed to slip around a sperm cell, drive it to an egg for potential fertilisation and then release it.
The researchers admit that much more work needs to be done before their technique can reach clinical testing, but the success of their initial demonstration (which can be seen in the video below) is a promising start.
The project builds on prior research into motors at a nanoscale. A separate team recently created submarines consisting of only 244 atoms that can be powered by ultraviolet light and are capable of moving one inch every second.