Researchers of the University of Jilin (China) created a four-legged mini-robot from sheets of Oxide Grafen. The robot is in effect due to changes in humidity level.
Previously, graphene sheets were subjected to such a chemical process as recovery, in which the substance loses oxygen atoms and acquires hydrogen atoms. Thanks to another trick —Only one side of the material — was processed;graphene sheets began to respond to a change in humidity. As soon as the humidity increases, the limbs of the mini-robot begin to contract. As the air dries, the material comes to its original state.
Scientists have found that when a relative humidity is changed from 33 to 86 %, it is possible to change the bend of the limb from 0 to 85 degrees. As a result of such manipulations, a mini-robot measuring about 1 cm in 12 seconds crawls 3.5 mm without the help of an additional
Source — Optical Society