Broken glass? Fix it quick with a press

In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces (above), then held their cross sections together for about 30 seconds until the glass repaired itself.
In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces (above), then held their cross sections together for about 30 seconds until the glass repaired itself. PHOTO: AGENCE FRANCE-PRESSE
Anticlockwise from top left: In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces, then held their cross sections together for about 30 seconds until the glass repaired itself.
In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces, then held their cross sections together for about 30 seconds (above) until the glass repaired itself.PHOTO: AGENCE FRANCE-PRESSE
Anticlockwise from top left: In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces, then held their cross sections together for about 30 seconds until the glass repaired itself.
In a lab demonstration, researcher Yu Yanagisawa broke a glass sample into two pieces, then held their cross sections together for about 30 seconds until the glass repaired itself (above).PHOTO: AGENCE FRANCE-PRESSE

Discovery paves way for highly durable glass that increases lifespan of products

TOKYO • A Japanese researcher has developed - by accident-a new type of glass that can be repaired simply by pressing it back together after it cracks.

The discovery opens the way for super-durable glass that could triple the lifespan of everyday products such as car windows, construction materials, fish tanks and even toilet seats.

Mr Yu Yanagisawa, a chemistry researcher at the University of Tokyo, made the breakthrough by chance while investigating adhesives that can be used on wet surfaces.

Does this mean you will soon be able to repair those cracks in your smartphone with a quick press of the fingers? Or surreptitiously piece together a shattered beer glass dropped after one pint too many?

Well, not quite. Not now and, in fact, not in the near future. But it does open a window of opportunity for researchers to explore ways to make more durable, lightweight glass-like items such as car windows.

In a laboratory demonstration, Mr Yanagisawa broke a glass sample into two pieces. He then held the cross sections of the two pieces together for about 30 seconds until the glass repaired itself, almost resembling its original form.

To demonstrate its strength, he then hung a nearly full bottle of water from the piece of glass - and it stayed intact.

STEP IN SAFETY AND DURABILITY

When a material breaks, it has already had many tiny scars that have accumulated to result in major destruction. What this study showed was a path towards making a safe and long-lasting resin glass. ''

MR YU YANAGISAWA, a chemistry researcher at the University of Tokyo.

The organic glass, made of a substance called polyether thioureas, is closer to acrylic than mineral glass, which is used for tableware and smartphone screens.

Other scientists have demonstrated similar properties by using rubber or gel materials, but Mr Yanagisawa was the first to demonstrate the self-healing concept with glass.

The secret lies in the thiourea, which uses hydrogen bonding to make the edges of the shattered glass self-adhesive, according to Mr Yanagisawa's study.

But what use is all this if it cannot produce a self-healing smartphone screen?

"It is not realistically about fixing what is broken, more about making longer-lasting resin glass," Mr Yanagisawa said.

Glass products can fracture after years of use due to physical stress and fatigue.

"When a material breaks, it has already had many tiny scars that have accumulated to result in major destruction," he said.

"What this study showed was a path towards making a safe and long-lasting resin glass" which is used in a wide range of everyday items.

"We may be able to double or triple the lifespan of something that currently lasts for 10 or 20 years," he added.

AGENCE FRANCE-PRESSE

A version of this article appeared in the print edition of The Straits Times on December 29, 2017, with the headline 'Broken glass? Fix it quick with a press'. Print Edition | Subscribe