The magnetic hammer mechanism may be useful for small surgical interventions in the future.

Researchers at the University of Houston have developed a magnetic hammer that sits inside a tiny robot which can move through mammalian brains.

Although this sounds like the plot of a science fiction movie, the invention could have important implications for the medical field.

Millirobots are already able to penetrate animal brain tissue in response to magnetic resonance imaging (MRI) scanners.

The latest invention consists of a tiny robot which contains a stainless-steel head that is moved back and forth inside the robot’s body. The tip of the robot’s nose is made from 3D-printed thermoplastic.

Magnetic field scanning technologies direct the motion of the robot.

The robot’s bead compresses a mechanical spring when pulled into one direction. When the spring is released, the robot is propelled forward and hammered deeper into the tissue.

Aaron Becker, assistant professor in electrical and computer engineering at the University of Houston, explains: “The robot is the combination of the MRI system and this relatively simple component that could be mass produced.”

The future of biopsies?

Although MRI scanners tend to restrict the movement direction of the robots, researchers sought to make the most of it.

As part of their initial trials, they successfully penetrated a range of animal brain tissues.

Eric Diller, an assistant professor of mechanical engineering at the University of Toronto, praised the magnetic hammer for amplifying “the amount of force achievable from magnetically driven millirobots.”

“The approach here is ingenious to boost peak forces, but there could be limits in applying this force in a more general way. Because it uses sliding parts, there could be difficulties in scaling the device smaller where friction and adhesive forces could jam the mechanism,” he added.

However, the robot does leave penetration wounds as it burrows through the tissue. Therefore, it’s not entirely certain what medical function it could perform without being deemed “invasive”.

According to the researchers, the robot could be used for small surgical interventions such as biopsies. For the future, they hope to design robots which can move through the cerebrospinal fluid to reach the spine.

It’s still a long way to go, but the magnetic hammer is certainly a good start.

Robot penetrating tissue. (Image: University of Houston)

Source: University of Houston & Spectrum IEEE