Imagine if you dropped your mobile device and didn't have to worry about breaking it, because you knew the phone would bounce harmlessly off the floor -- and, even if it were damaged, it could repair itself.
That's the promise of a new material developed by researchers at the IK4-CIDETEC Research Center in Spain that can fuse back together in two hours after being severed. The polymer-based material uses "a poly(urea-urethane) type composition, a material which is widely used in industry," the researchers said in a press release.
A YouTube video (below) shows a researcher cutting a solid cylindrical-shaped piece of the material in half. The two halves are put back in contact with each other and left to sit at room temperature for two hours. In that time, according to the video, the material connects back together as a single piece of polymer that doesn't separate when the researcher stretches it.
This catalyst-free healing occurs without any intervention or other material agents, the researchers wrote in a paper (registration required) published by the Royal Society of Chemistry journal Materials Horizons.
In the paper, the researchers discuss the key to the material's self-healing capability:
A particularly useful approach to generate self-healable polymers has been the introduction of reversible or exchangeable bonds into the polymer network. The idea behind this is to reconnect the chemical crosslinks which are broken when a material fractures, restoring the integrity of the material. This is expected to provide polymers with enhanced lifetime and resistance to fatigue. Self-healing approaches based on such dynamic crosslinks have been carried out using both reversible covalent chemistries and supramolecular interactions.
The self-healing polymer could have a wide range of applications in the commercial, industrial, and aerospace sectors, where damage to materials could be harmful not only to the device, but also life threatening.