Sperm-like Microbots Could Make Drug Delivery More Efficient, Study

Researchers have developed robots that look and swim like sperms. The "brobots" can be controlled by oscillating weak magnetic fields.

Several scientists are trying to copy nature to make robots. The new research demonstrates that it is possible to create tiny, simple robots that can be controlled using magnets.

Researchers call the robot MagnetoSperm. They say that the bot could be used to enhance drug delivery, clean clogged arteries and even help in-vitro fertilization. The study is published in the journal Applied Physics Letters

The sperm-like robot, constructed by scientists at the University of Twente (Netherlands) and German University in Cairo, is just 322 micron long. The robot has a head coated in cobalt-nickel layer along with an uncoated tail. An oscillating magnetic field - of less than five millitesla - is enough to move the bot. The magnetic field is as strong as that of a decorative refrigerator magnet.

When the weak magnetic field is applied, the robot experiences a torque on its head. The torque causes the flagellum to oscillate and propel it forward, according to a news release.

The team chose a polymer called SU-8 to make the robot because it is easy to fabricate and is mechanically stable. This polymer was coated onto a silicon wafer. Researchers used electron beam evaporation to add cobalt-nickel layer to the head of the micro-robot.

"Nature has designed efficient tools for locomotion at micro-scales. Our microrobots are either inspired from nature or directly use living micro-organisms such as magnetotactic bacteria and sperm cells for complex micro-manipulation and targeted therapy tasks," said Dr. Sarthak Misra, principal investigator of this study and an associate professor at the University of Twente, in the news release.

"As technology progresses and many products get smaller, it becomes difficult to assemble objects on nano- and micro-scales," said Dr. Islam Khalil, an assistant professor of the German University in Cairo. "MagnetoSperm can be used to manipulate and assemble objects at these scales using an external source of magnetic field to control its motion."

The team plans to scale-down the size of the micro-bot and find a magnetic nanofiber that can act as a flagellum.