According to a recent report from the US Daily Science website, biological tissue has complex mechanical properties-flexible and strong, but synthetic materials are difficult to reproduce these characteristics. Now, an international team has produced a biocompatible synthetic material that not only has the mechanical properties of biological tissues, but also changes color when deformed, just like the skin of a chameleon. The researchers said that the new materials are expected to play a role in the field of biomedicine.

In order to produce medical implants, materials with similar mechanical properties to biological tissues need to be selected to reduce inflammation or necrosis. Many tissues, including the skin, intestinal wall, and myocardium, are very soft but harden when stretched. So far, synthetic materials have not been able to reproduce this behavior.

In the latest experiments, researchers used unique triblock copolymers to develop a compound with biological tissue properties-a physically crosslinked elastomer (artificial rubber), which consists of a central block on the central block "Grafted" side chains like bottle brushes.

They found that by carefully selecting the structural parameters of the polymer, the strain curve of the new material was the same as that of biological tissue (pigskin in this study). The new material is also biocompatible because it does not require additives such as solvents.

In addition, the new material can change color when deformed. Scientists explain that this physical phenomenon is caused by light scattering from the polymer structure. Atomic force microscopy and X-ray diffraction experiments show that the terminal blocks of these polymers are assembled into nanospheres and distributed in a brush-like polymer matrix. Light will interfere with this micro-phase separation structure, and the spheres will have different colors due to different distances, so when the material is stretched, it will change color.

The researchers said that the mechanical properties (elasticity, strain curve) and optical properties of the newly synthesized polymers are unprecedented. By adjusting the length or density of the "brush" side chain, these characteristics can be adjusted, which is expected to develop medical implants or personalized fakes. Body (vascular, intraocular implants, etc.) and materials with new resilience.

The latest research was carried out by the French National Academy of Sciences (CNRS), the European Synchrotron Radiation Laboratory (ESRF), and American scientists. The paper was published in the latest issue of the journal Science.