Researchers print self-healing skin for robots

Living materials such as animal bones or plant stems are able to heal themselves, regenerate, adapt to the environment and even make certain choices. A team from the Swiss Federal Institute of Technology in Zurich (ETHZ) wanted to take advantage of this property, the researchers write in the study.

To do this, the scientists used a 3D printer to print a three-dimensional lattice of a hydrogel loaded with a fungus called the glossy lacquer polypore (Ganoderma lucidum, pictured below). Similar to mold on food, the so-called fungal mycelia, ie the root network of the fungi, populated this printed grid.

Firm skin regenerates itself
This resulted in about 20 days in a skin that is robust on the one hand and has the ability to regenerate itself on the other. If you cut it, it grows back together. The skin owes its ability to heal itself to the metabolic activity of the mycelial cells. These have evolved in nature to navigate and grow in the openings of porous structures.

Mushroom skin needs nourishment
In order for the skin to grow again after damage, it must not lose this metabolic activity. And for that she needs nutrients. How exactly this fungal skin can be fed needs further research, according to the research. In addition, it is still unclear how waste can be disposed of over a long period of time.

To test the process, a robot skin was printed at the ETHZ and several tests were carried out with it. They made a robot hand with the printed skin roll over different surfaces and dive into the water. The printed mushroom skin passed all these tests with ease. In the future, this technology should “bring life to the world of materials,” the study authors wrote.