Pissrubber

A material that is able to self-repair even when it is sliced in two has been invented by French researchers.

The as-yet-unnamed material is made from vegetable oil and a component of urine, forming an artificial rubber. When cut, the surface of the substance retains a strong chemical attraction, and pieces of the material join together again as if never parted without the need for glue or a special treatment.

The trick was to replace the covalent bonds in rubber with weaker connections known as hydrogen bonds. These are like hands on neighboring molecules that can clasp together, but let go when broken. Once this had been done, not only could the new rubber could be recycled and remolded many times over, but the chemical hands at the fresh surfaces would be ready to bind again.

Using a razor blade in a demonstration, a thin strand of the yellowish material was severed and then pressed them together. Almost immediately, the grip was strong enough to hold the sample just at one end. Within an hour the bonds had rebuilt themselves so thoroughly that it was possible to stretch the strand to twice its length without any sign of weakness where the cut had been made.

The material was developed with the support of the French company Arkema, which is determining potential uses and commercial products.