Japanese researchers discover self-healing glass

20 December 2017

Japanese researchers claim to have discovered a new type of glass that can heal itself from cracks and breaks.

Glass made from a low weight polymer called ''polyether-thioureas'' can heal breaks on pressing together by hand without the need for high heat to melt the material.

The research, published in Science, by researchers led by professor Takuzo Aida from the University of Tokyo, promises glass that can heal itself and with could be potentially be used in phone screens and other fragile devices.

While self-healing rubber and plastics have been developed already, according to researchers, the new material is the first hard substance of its kind that can be healed at room temperature.

''High mechanical robustness and healing ability tend to be mutually exclusive,'' wrote the researchers, saying that while some hard but healable materials have been developed, ''in most cases, heating to high temperatures, on the order of 120C or more, to reorganise their cross-linked networks, is necessary for the fractured portions to repair.''

They add that the new polymer glass is,  ''highly robust mechanically yet can readily be repaired by compression at fractured surfaces''.

The properties of the polyether-thioureas glass were accidentally discovered by a graduate school student Yu Yanagisawa. He was preparing the material as a glue. He observed the edges of the polymer would adhere to each other, healing to form a strong sheet after being manually compressed for 30 seconds at 21C.

Yanagisawa told NHK that he did not believe the results at first and repeated his experiments multiple times to confirm the finding. He said, ''I hope the repairable glass becomes a new environment-friendly material that avoids the need to be thrown away if broken.''

The material could find application as a healable screen for devices such as smartphones, according to experts.

Research commissioned by repair firm iMend in 2015, showed that over 21 per cent of UK smartphone users were living with a broken screen, with smashed displays being one of the biggest issues.

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