Editor's take: Researchers from the City University of Hong Kong have developed a special type of spray that can give objects magnetic properties. Through the use of an external magnetic field, the coated objects can be made to roll, crawl and walk without any direct contact. It could be a potential game-changer in the medical field.

The coating, called M-spray, is less than a quarter of a millimeter thick and is comprised of gluten, polyvinyl alcohol and iron particles. It can stick to textured and smooth surfaces alike, can be redistributed after the fact for improved application flexibility and can even be dissolved on command.

The most obvious application for M-spray is in the medical field. In testing, the team was able to administer capsules to anesthetized rabbits and control / track their movement through the stomach. When the capsules reached their intended target, their outer coatings were successfully dissolved, allowing for targeted treatment with medicine.

"The disintegrated coating could be absorbed or excreted by the human body," said lead researcher Dr. Shen Yajing.

Outside of medicine, the team believes the spray could also be useful in the fields of transportation and movable sensors, especially in applications with limited space. I'm sure there's also some built-in joke about magnetic perfume and attraction, but I won't go there.

The researchers' full write-up can be found in the journal Science Robotics.