University of New South Wales (Sydney): Engineers have demonstrated a way to help 3d printed plastic heal itself at room temperature using only standard Led lights for around one hour which causes a chemical reaction and fusion of the two broken pieces.

The researchers in the UNSW School of Chemical Engineering 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.
The entire process makes the repaired plastic even stronger than it was before it was damaged, and it is hoped that further development and commercialisation of the technique will help to reduce chemical waste in the future.
That is because 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.
Researchers says that the new technology could potentially be used in a range of applications where advanced 3D printed materials are currently used in high-tech specialized components. These include wearable electronics, sensors, and even some shoe manufacturing.