Disturbing Robotic Slime Can Move Around Inside the Body, Pick Up Objects

Scientists working at the Chinese University of Hong Kong have created something that looks horrifying, and only gets more upsetting when you learn it’s designed to crawl around inside your body. The appropriately named “magnetic slime robot” doesn’t need any internal electronics — it’s a combination of several different materials, allowing it to be controlled with external magnetic fields. The result is a wriggling, brown blob that could one day scoop harmful objects out of the human digestive tract. That should pair nicely with your nanoparticle toothbrush.

The slime bot has a structural matrix composed of polyvinyl alcohol and borax, which is a common constituent of cleaning products. This mixture is doped with magnetized neodymium particles. That makes the ooze sufficiently magnetic that it can be influenced by other magnets placed outside the body. The researchers, led by Professor Li Zhang, have done laboratory testing that shows how the slime bot could navigate a human stomach and retrieve a potentially dangerous object.

Since there are no internal electronics, the slime robot can’t operate alone. Doctors would have to use imaging to locate an object and guide the slime to the right location. When it gets there, the team has shown that it can successfully envelop small objects like a coin cell battery. It forms C and O shapes quite easily to ensnare the target. Then, you can simply drag the foreign material out with a magnet.

According to the researchers, the magnetic slime robot has a consistency like custard, a famously non-Newtonian fluid. That means the ooze behaves differently depending on how much force it encounters. When moving slowly, it flows like a liquid. When struck, dropped, or moving quickly, it behaves more like a solid. It can even merge back together if part of the blob gets separated.

Neodymium magnets are not a new technology, so why has nobody made a disturbing slime robot before? These particles are potentially toxic to humans, so your first instinct would not be to send them in after another hazardous object. However, the team compensated for this by coating the slime bot with a layer of silica to contain the magnetic particles. Zhang believes it would be safe to send the robot into the body for short periods of time — this is a future topic of study. The team also showed that the slime bot could have other applications. It’s conductive, so it could also slither into tight spaces to reconnect severed wires.