New 3D-printed plastic can heal itself with light

The scientists added a special powder to the 3D-printed plastic so that when it breaks, it can be simply repaired on-site.

Professor Cyrille Boyer, along with two experts Nathaniel Corrigan and Michael Zhang at the University of New South Wales' School of Chemical Engineering (UNSW) have found a new way to help 3D printed plastics heal themselves at room temperature with just light. , Phys on December 18 reported. The study results were published in the journal Angewandte Chemie International Edition.

Additive 3D printed violins can self-heal when placed under ultraviolet LED light.

The team of scientists added a special powder to the liquid plastic used in the printing process, which facilitates repair when the material breaks. This can be done very easily by shining a standard LED light on the 3D printed plastic for about an hour, creating a chemical reaction and fusing the two fragments. The whole process makes the healing plastic even stronger than it was at first.

The researchers hope that the development and commercialization of the new technique will reduce chemical waste because broken pieces of plastic do not need to be thrown away or recycled, and can be simply patched even while in use. mounted in a component composed of many other materials. The new technology has potential applications to wearable electronics, sensors, even in the shoe manufacturing process.

"You can apply this technology in many places, for example places where polymer materials are used. If a part breaks, you can repair it without throwing it away. The environmental benefits are obvious because you don't have to. need to reassemble a whole new material each time it breaks. We're extending their lifespan, helping to reduce plastic waste," said Corrigan.

The powder additive the team used is trithiocarbonate, developed by the Australian Scientific and Industrial Research Organization (CSIRO). It allows to rearrange the nanoscale lattice of the elements that make up a material and to fuse fragments. This happens within 30 minutes when the ultraviolet LED shines directly on the broken part. The resin will heal completely in about an hour. Tests, including testing on a 3D-printed violin, show that the healed plastic is very strong.

Given the simplicity and speed of the new process compared to current 3D printing methods of repairing materials, the team thinks commercialization is possible.

"There are other processes but rely on thermal chemistry to repair the material, which typically requires about 24 hours and many heating cycles to achieve the same result. Another limitation is the need for a furnace to be heated at high temperatures and the plastic material cannot be repaired on site. Staff must first disassemble it from the item, which adds complexity and delay," Corrigan said.

"With our system, you can leave the broken plastic in place and shine the light on the whole thing. Only the additives at the surface of the material are affected, so the repair process will be easy. faster and faster," he said.