Using a magnetic surface, any object can be transformed into a robot controlled by a magnetic field. The magnetic mantle can be applied easily with the help of a magnetic spray and the robot can perform a variety of movements. It can walk, roll, crawl or otherwise move. Researchers from City University of Hong Kong (CityU) and their collaborators at the Shenzhen Institute of Advanced Technology and Chinese Academy of Sciences are behind the production of this technology.


Manufactured robots are the size of insects and are called milirobots. They can adapt to different environments for research, remote sensing or biomedical applications. M-spray is used to create these robots. It is a magnetic spray that applies a special composite adhesive.

“Our idea is that, by putting on this magnetic coat, we can turn any object into a robot and control their locomotion,” says CityU engineer Yajing Shen, who led the research published in the journal Science Robotics. “The M-spray we developed sticks on the targeted object and activates it when driven by a magnetic field.”

Credit: City University of Hong Kong

Use of spray

In a special spray we find particles of polyvinyl alcohol, gluten and iron. This spray will create a layer that adheres very well to any surface in 2D and 3D objects. The formed layer is very thin, the film is only 0.1-0.25 mm thick. As the layer is very thin, the original size and shape of the object will be preserved. After applying the magnetic layer, the alignment of the magnetic particles in the coating with a strong magnetic field is programmed. This adjusts how the billionaire will move.

Use in medicine

Magnetic robots can be created from many objects, from cotton thread to origami, soft foil or plastic tube. Depending on the material and shape, the robots are then capable of various movements. Magnetic particles can be reprogrammed at any time to ensure that the robot changes the way it moves. This will help the robots to cope with the different types of obstacles they will get in the way. The ingredients in M-spray are biocompatible and can break down in the body if needed.

It is therefore widely used in the field of medicine. For example, an M-spray coated tablet can be taken to a specific place in the body. In the same way, for example, the catheter can be moved to get to the right place and perform smooth and sharp turns. When a medical object is needed in place, the magnetic surface disintegrates.

“The controllable disintegration property of M-spray enables drugs to be released in a targeted location rather than scattering in the organ,” Shen says.

The plan is to improve the capabilities of M-spray to withstand the different environments in the human body. The use of this technology in other areas is also being investigated.


Image credit:
City University of Hong Kong