Scientists at ETH Zurich built on the self-healing properties of materials such as animal bones or plant stems. They used a 3D printer to create a grid made of hydrogel loaded with the Ganoderma lucidum fungus. Similarly, to food mould, fungal mycelia then colonised this printed grid. In about 20 days, the result was a skin both robust and capable of self-regeneration: when cut, it grows back. The skin owes this self-healing ability to the metabolic activity of the fungal mycelial cells, which have evolved in nature to be able to navigate and grow through the openings of porous structures.
However, in order for the skin to regenerate itself, it must not lose this metabolic activity, for which it needs nutrients. According to the study, the way in which the fungal skin can get this nourishment still needs further research. It is also not yet known how the waste products can be removed over a longer period of time. To examine the process, the ETH researchers printed a robot skin and carried out several tests, such as rolling the robot over various surfaces and immersing it in water. The printed skin passed all tests without problems.
More information:
https://www.swissinfo.ch/eng/sci-tech/swiss-researchers-create-self-healing-skin-for-robots/48170340