A new type of glass has been discovered that can be easily repaired at low temperatures.
Cracked windscreens and phone screens may soon be a thing of the past. Japanese researchers have just developed a type of glass that can heal itself from cracks and breaks. Most screens are made from high molecular weight polymers, which are robust enough to withstand everyday use, but are difficult to repair once cracked. This is because the polymer chains are too heavily entangled to be easily rejoined once broken, and require temperatures of around 120 degrees celsius or higher in order to reorganise their cross-linked strands. Now, a group of researchers, led by Professor Takuzo Aida from the University of Tokyo have found a way to make glass that can be sealed at much lower temperatures.
Grad student Yu Yanagisawa was preparing a low molecular weight polymer to use as a glue, by combining the polymer polyether with the sulfur compound thiourea. He discovered that once cut, the edges of the new substance would stick together again after pressed for 30 seconds at just 21 degrees celsius. Yanagisawa reported that he had to repeat his experiments several times before he believed the results. His hope is that the self-repairing glass can reduce the need to throw away or replace broken items, leading to less waste.
While smartphone manufacturers have already experimented with some self-healing materials, these have only been capable of healing minor scratches. Given that a 2015 report by Motorola found that 30 percent of smartphone owners in America were walking around with a broken screen, Yanagisawa’s discovery is bound to meet with relief from phone owners and manufacturers. We have already seen a soft robot hand that can repair itself when heated and a bioplastic that can self-heal using water. Will the new glass join these self-healing materials to make cracked and broken screens a thing of the past?