Researchers in Germany have used nanotechnology to create amazing paper. With all the outward signs of an ordinary paper sheet, “nanopaper” with a simple click of an electric toggle switch becomes soft, like a rag, and restores the hardness of the power outage field. Moreover, the stiffness can be controlled by changing the voltage level. Such a property, for example, can help in the creation of materials that automatically damp shocks.

Nanopaper is like a sheet of plain paper. Image source: VadimVasenin / Depositphotos

As a starting point for research, scientists from the University of Johannes Gutenberg in Mainz and the University of Freiburg took a substance from the walls of wood cells, such as cellulose nanofibrils. It, for example, can be obtained from wood waste. The particles of this material are much smaller than ordinary cellulose fibers, therefore, even transparent, and much stronger “paper” can be made from them.

In the course of experiments, it was found that when an electric current is applied to such a “nanopaper”, it heats up and the bonds of cellulose nanofibrils fibers with each other are destroyed. This leads to the fact that the material completely or partially loses its rigidity – it softens. Relieving stress restores bonds at the intersection of nanofibers and returns the material to its original stiffness.

Illustration from an article in Nature. Image source: Nature

Interestingly, the scientists did not stop there and are going to improve the material to such properties so that it can independently accumulate a charge and use it if necessary. Such a property will help to set a certain response threshold for the material to absorb the load energy. Instead of all sorts of automation, which can be done today, material with a reserve of energy on board can, using simpler means and very selectively, damp shocks and increased loads, for example, in a car accident.