Korean developers from the National Seoul Institute invented the simplest robots that move with water.
Where does this idea come from
As is often the case, the invention of the researchers was inspired by nature. There are plants that change the shape and condition of their leaves, depending on the amount of liquid: dissolve, if it is not enough and fold, when "full".
The robot copies the behavior of these plants and uses water as a source of energy. This method, in contrast to the batteries, which contain toxic substances, is not harmful and does not pollute the environment. Also, these robots can be useful for medical purposes to send medicines into the human body.
How it works
The robot has two layers of nanofibers, one of which absorbs water, and the second one does not. On the wet surface, the first begins to swell and contract. Drying, the fiber straightens back, which causes the machine to move.