UNSW engineers have utilized a new technique to help 3D printed plastic heal itself at room temperature using only lights.
UNSW professor Cyrille Boyer and his team, Dr Nathaniel Corrigan and Mr Michael Zhang, have shown that the addition of “special powder” to the liquid resin used in the printing process can later assist with making quick and easy repairs should the material break.
This can be done by just shining standard LED lights on the printed plastic for around one hour which causes a chemical reaction and fusion of the two broken pieces.
The powdered additive the UNSW team uses is a trithiocarbonate, known as a reversible addition fragmentation chain transfer (RAFT) agent which was originally developed by CSIRO.
The RAFT agent accordingly enables rearrangement of the nanoscopic network of elements that make up the material and allows the broken pieces to be fused.
This occurs within approximately 30 minutes when UV LED lights are shone directly onto the broken plastic, with full healing taking place after roughly one hour.
The best part about the whole process is that it actually makes the repaired plastic even stronger than it was before it was damaged.
The end goal is to make the technique even better by ridding the process’ chemical waste in the future: broken plastic parts would not need to be discarded, or even recycled, and could be mended simply even when remaining embedded in a component including many other materials.
“In many places where you use a polymer material, you can use this technology. So, if a component fails, you can repair the material without having to throw it away,” contends Corrigan.
“There is an obvious environmental benefit because you’re not having to re-synthesize a brand-new material every time it gets broken. We are increasing the lifespan of these materials, which is going to reduce plastic waste.”
According to Boyer, the new technology could potentially be used in a range of applications where advanced 3D printed materials are currently used in high-tech specialised components.
These include wearable electronics, sensors, and even some shoe manufacturing.
Image and content: EY/UNSW