Self-healing material can build itself from carbon in the air: #Regenerative
http://news.mit.edu/2018/self-healing-material-carbon-air-1011
A material designed by MIT chemical engineers can react with carbon dioxide from the air, to grow, strengthen, and even repair itself. The polymer, which might someday be used as construction or repair material or for protective coatings, continuously converts the greenhouse gas into a carbon-based material that reinforces itself.