The swimming nanorobots are made of oil and water.

Image I

Phys.org is an article about an oil-based swimming robot. Those robots are using use fluctuating temperature changes in their surrounding environment to store energy and to swim. But by using electromagnetic systems is possible to get more accuracy for that kind of system. In the simplest version of the oil, the droplet is connected to the microchips, where is the electrical resistor. 

That changes the temperature in the oil drop to the direction where the controller wants. But the most interesting version is to combine that thing with slime molds. Researchers can adjust the direction where the slime molds are growing and moving. And in this version, the slime mold is controlling the direction, where the oil droplet is traveling. In this case, the slime mold can be used as the "brains" for that kind of system. 

Those oil drop robots are not harmless, because they can slip into the veins of living organisms and cause blockages. In medical use, those oil-drop robots can close veins that are transporting nutrients for the tumor cells. If some cell is eating the oil drop, there is a microchip, that microchip can damage the core of the cell. Or those oil drops can fill the cells, and destroy them. That thing opens new ways to handle cancer and infections. But in the wrong hands, those things are the most dangerous weapons in history. 

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The new swimming robots can form by using the oil drops, and the idea is that the robot can swim or slide on the water. They are rechargeable what allows to use to collect waste from water. If a robot can dive it can form a large entirety, which surrounds the waste. And then that oil drop, where is the chemical inside it can suck to the tank. 

The sliding oil drop can be made by adjusting the surface tension in the different areas of the robot drop. In that case, the robot can move in the direction, where the researchers want. But how this thing can make in real life? The problem is how to make a large number of those robots? 

The idea is simple the food oil is consisting chain-looking molecules. If the ends of those molecules are put the atom, like iron what interacts with the magnetic, is possible to pull the oil molecule in a certain direction. The researchers can make the same thing by using the string-looking molecule, which is connected to the oil molecule, and then the electricity or chemical reaction will make the string pulling the molecule in a certain direction. 

Then the entire drop can cover by using iron-based dust. In that case, there are no microchips in the oil drop. And the control of that thing happens by using the different radio frequencies, which are inducting electricity in a certain group of iron bites. 

The idea is that if certain bites of dust are reacting with the different radio frequencies, that allows inducting the electricity to the certain bites of the iron dust. Then that thing allows controlling the direction, where the oil drop is moving. And the requirement is that if we want to make the drop, which travels in four directions, the system would cover the drop by using four types of molecular radio receivers. 

()https://phys.org/news/2021-07-scientists-rechargeable-microrobots-oil.html

()https://scitechdaily.com/slimy-action-at-a-distance-thinking-without-a-brain/

()https://www.worldofchemicals.com/457/chemistry-articles/meet-the-organic-molecules-in-organic-foods.html

Image I:()https://phys.org/news/2021-07-scientists-rechargeable-microrobots-oil.html

Image II:()https://scitechdaily.com/slimy-action-at-a-distance-thinking-without-a-brain/