Scientists have accidentally created the first-ever permanently magnetic liquid. According to the new study, the liquid droplets can change into various shapes. They can also be externally manipulated to move around freely.
We generally know magnets to be solid. However, according to Thomas Russell, a professor of polymer science and engineering at the University of Massachusetts, Amherst, this isn’t always true. He says, “We can make magnets that are liquid, and they could conform to different shapes — and the shapes are really up to you.”
Russell explained that the liquid droplets can change shape from a sphere to a cylinder. He added that they can even make it look like a sea urchin if they wanted. The team lead by Russell also revealed that they made the liquid magnets by accident. They were experimenting with 3D printing liquids at the laboratory when it happened.
They only wanted to create solid materials that had the characteristics of liquid for energy applications. But things changed when a lead author, Xubo Liu, and a post-doctorate student noticed 3D-printed materials spinning around. The materials, made from magnetised particles called iron-oxides, moved together on a magnetic plate.
Upon further investigation, the team realised that it was not only the particles but the whole construct had turned magnetic. They created small-sized droplets with water, iron-oxides, and oil using a 3D-print liquid technique. The liquid droplets were able to keep their shape because of the presence of surfactants. Some of the iron-oxide particles bonded with these substances that reduce the surface tension of a liquid.
These substances create a film around the liquid that serves a barrier for the rest of the enclosed particles. The team now placed the water droplets near a magnetic coil to turn them to magnets. However, to the surprise of the scientists, the droplets remained magnetised even after being separated from the magnetic coil.
When they placed these droplets with a magnetic field, the iron-oxide particles in it all aligned in the same direction. Once the magnetic field was removed, the iron-oxide particles stayed immovably bound to the surfactant in the film. However, the droplets inside the stay aligned.
Russel says they haven’t been able to understand why this happens, but he believes it will pave the way to some amazing inventions. “For me, it sort of represents a sort of new state of magnetic materials,” he added.