A new 3-D printed gel that can ‘heal’ like living tissue — and change form in response to environments — could have uses ranging from fixing cracked phone screens to adaptive camouflage.

Researchers at the University of Melbourne (www.unimelb.edu.au) in Australia said that, if successfully developed, the polymer-based substance could have endless applications, including the ‘healing’ of interior and exterior car scratches.

The gel-like ‘ink’ starts off similar in texture to toothpaste, but it can flow when pressure is applied, becoming stable again when the pressure is removed.

Researcher Luke Connal said: “After being printed, parts can heal a crack — or even a cut — and regain their original strength.” Led by PhD student Milena Nadgorny, Dr Connal’s team has had a paper published in The Royal Society of Chemistry’s Molecular Systems Design & Engineering journal.

The team’s report said: “Self-healing materials are capable of recovering from damages and restoring their functionality, just like the natural ability of living creatures to repair their tissue.

“This unique property offers the ability to extend the lifetime of products, which is usually limited by mechanical failures.”

Dr Connal added: “The healing process is based on dynamic covalent chemistry; this means we can form, break and reform chemical bonds. When we can do this in a controlled and triggered manner, it is possible to manipulate the properties of printed objects.

“The next step is investigating how to increase the material’s strength and flexibility — and even its ability to change colour.”