TOKYO (REUTERS) - As many smartphone users know all too well, when the glass screen breaks it's time for a new one.

Unless it was made of this glass.

Developed at the University of Tokyo and made from a lightweight polymer - it sticks back together with the slightest pressure.

Researcher Yu Yanagisawa said: "I often get told... how it is really problematic when smartphone screens break. But if the broken pieces have become powdery, it is hard to press together and repair.

"Soft things are easy to repair, but the harder, more inflexible, and stronger the material is, the self-repairing property disappears. I had to find that point of balance."

Usually, glass is repaired by being melted at high temperature but this material will bond with itself at room temperature.

The researchers say a material that can fix cracks as they appear could combat material fatigue in many applications in the future.

But for long suffering clumsy smartphone users, this new glass cannot come soon enough.