Liquid droplets have been developed that behave like tiny bar magnets.
Even though there has been evidence of some liquids having magnetic particles, the magnetism tends to get jumbled when the magnetic field loses it. But researchers from Berkeley Labs noticed that by adding certain types of polymers to the recipe, permanently magnetized liquid droplets are possible. As a result of this creation, soft robots or capsules that could be magnetically steered through the body could be used to deliver drugs to specific cells.
To create this concoction, team members submerged millimeter-sized droplets of watery solution containing iron-oxide nanoparticles in oil peppered with polymers. The polymers drew many of the magnetic nanoparticles to the droplets’ surface and pinned them, forming a packed shell of nanoparticles. When exposing these droplets to a magnetic field, the magnetic poles of the nanoparticles are forced to point in the same direction.
The magnetism is so strong that it keeps the nanoparticles free-floating and behaving like a solid magnet. Ultimately, these magnets could help soft robots get around rather than relying on inflatable air pouches or electric currents to move. Magnetic sponges or stretchy polymers could also be in the works with this new creation. But now that it’s a possibility, the ideas for its most effective use will surely come flying in!