(Image: IFW Dresden)
Medical researchers at the Dresden Institute for Integrative Nanosciences wanted to find new ways to deliver drugs to targeted parts of the body. Prof. Oliver G. Schmidt led the search for what he calls a "biological motor"--a microscopic delivery system.
Human sperm cells are very fast, strong, and determined swimmers. They're easily available in large quantities. So the researchers realized that if pharmaceutical payloads could be attached to these cells and then the sperm aimed in a particular direction, they could be used to treat illnesses. Discovery reports:
To create these tiny robots, the scientists first had to catch a few. First, they designed microtubes, which are essentially thin sheets of titanium and iron — which have a magnetic property — rolled into conical tubes, with one end wider than the other. Next, they put the microtubes into a solution in a Petri dish and added bovine sperm cells, which are similar size to human sperm. When a live sperm entered the wider end of the tube, it became trapped down near the narrow end. The scientists also closed the wider end, so the sperm wouldn’t swim out. And because sperm are so determined, the trapped cell pushed against the tube, moving it forward.
Next, the scientists used a magnetic field to guide the tube in the direction they wanted it to go, relying on the sperm for the propulsion.
Each spermbot is capable of traveling up to 100 micrometers per second, which is similar to a 6-foot-tall human swimming 160 ft (50 meters) in 14 seconds.
-via Kevin D. Willamson