The Japanese have created a hydrogel that works like an artificial muscle

Researchers at the Japanese RIKEN Institute have created a hydrogel that changes shape depending on temperature. In this case, the gel structure makes the deformation directed - it significantly changes its linear dimensions in only one direction. The amount of liquid absorbed by the gel during such deformations remains constant.



Conventional hydrogels are known for absorbing a large amount of liquid several times their own weight. Absorbing liquid, they uniformly increase in volume, and to reduce it they need to give it away. And this process takes quite a long time.

The unusual hydrogel obtained by the Japanese works like an artificial muscle . With increasing temperature, it is significantly stretched in one direction, and slightly compressed in others, maintaining the original volume. A square sample becomes rectangular, and a corner made by scientists from this material briskly walked on a flat surface.



When creating the material, the previous achievements of scientists were used, in which they coagulated the polymer into a hydrogel using light, and created thin films of metal oxide using magnetic fields. This material consists of many layers of nanoscale bonded together by a polymer, between which electrostatic repulsive forces act. As a result, with increasing temperature, repulsion begins to prevail, and the material expands in one direction, increasing the distance between the layers.

Yasuhiro Ishida, one of the researchers, explains that scientists sought to create material expanding in one direction, but at the same time, its properties, such as volume retention and the ability to work without liquid, in air, came as a surprise to them. How to exceed expectations and a high deformation rate of about 70% of the length per second.

While scientists are conducting further research in this area. Such material can be used as artificial muscles, for example, in any valves that must quickly respond when the temperature changes.