Scientists have created self-folding graphene paper that could eventually be used to create artificial muscles, tiny robots, or smart clothing that automatically adjusts when the weather changes. It’s a bit like origami, but the paper is thinner, conductive, and 200 times stronger than steel. Researchers from Donghua University in China demonstrated that graphene paper can fold into a device that can walk forward and backward and even change directions.
“Compared with other kinds of self-folding materials, the all-graphene-based structure is simpler, its response behavior is faster and the output is more efficient,” researcher Jiuke Mu told Live Science. “More importantly, its origami and walking behavior is remotely controlled.”
Instead of using pure graphene sheets, the researchers used graphene oxide (GO), which is cheaper and easier to create. This material does not have quite the same impressive properties as pristine graphene, but it is a good alternative that shares many of the same characteristics. The researchers treated sections of the paper so that they would naturally absorb water vapor from the atmosphere. Then when the paper is heated, this water is released, triggers sections to shrink and bend. The process is reversed when the heating stops. The researchers used a near-infrared laser to wirelessly control the self-folding devices they built.
In a paper published in Science Advances, the researchers conclude: “We believe that these devices have the potential to be adapted to a wide range of applications such as sensing, artificial muscles, and robotics. The present study also provided a practical method for future large-scale preparation of self-folding devices using an approach similar to printing.”
Source: Live Science