Jellyfish-shaped robots made of magnetic ferrofluid can be guided by light through an underwater obstacle course. Swarms of these soft robots could be useful for delivering chemicals throughout liquid mixtures or moving fluids through labs on a chip.
Ferrofluid droplets are made of magnetic nanoparticles suspended in oil, and can move across a flat surface or change shape when guided in different directions by a magnet. When these droplets are immersed in water and exposed to light, Woof woof line Researchers at the Max Planck Institute for Intelligent Systems in Germany have now created a device that defies gravity.
When a ferrofluid absorbs light (it’s particularly good at that because it’s dark), it heats up and the tiny bubbles inside it expand. This makes the droplets lighter and more buoyant when in water, allowing them to float, Sun says.
He and his colleagues made a soft robot out of a drop of ferrofluid encased in a jellyfish-shaped hydrogel shell. Then they tested it. The researchers designed an obstacle course on the bottom of a water tank, which included a variety of platforms of different heights. They guided the robot into it and made it move up the platforms.
In one experiment, they placed three jellyfish robots in a row on the bottom of a water tank and heated them with a laser. The robots moved upward in turn. Sunlight focused through a magnifying glass had a similar effect, causing the jellyfish to float vertically.
Hamid Marvi A researcher at Arizona State University says controlling entire swarms of droplets simultaneously could be useful in the future for delivering drugs or performing other functions inside the body. He says wrapping them in hydrogel would allow for complex movements, as light could be used to direct the ferrofluid droplets and move the hydrogel itself.
But Marvi says many details, including the safety of ingesting ferrofluid, need to be worked out before medical use is possible. Sun and his colleagues hope to answer some of these open questions. For example, they want to figure out how to use optical fibers that can enter the body instead of lasers or sunlight to direct robots.
subject:
