Self-healing ‘blood’ polymer

We’ve heard about self-healing materials and we can all imagine their uses. Now, a team from the US has developed a new self-healing polymer that works similar to the way clotting blood forms a healing network around a wound.

Of further interest is that the innovation can heal holes and cracks around 35 mm across. This is over 100 times as much as before. This is a huge advantage, as we can now expect such self-healing polymers (SHPs) to be a useful addition to smartphone screens, windscreens, clothing and much more.

The material design is inspired by the natural blood-clotting system found in many animals: a system of capillaries, or tiny tubes, that pipe the required material to the ‘wound’, a crack, tear or cut.

This new SHP is a development from much earlier work. In 2001, the team developed a plastic that contained micro-capsules with a healing chemicals. Wherever cracks appeared, the capsules would break, releasing the healing liquid.

Now, two separate chemicals are piped through the network of capillaries to the damaged area. These materials work together in stages to repair the crack. First, the chemicals form a network that loosely bridges the gap. This scaffolding is similar to the gel-like covering that helps heal wounds in human skin.

Within 20 minutes, this network with gel-material dries and hardens, thus repairing the break. However, the new material is weaker than the original, recovering a little over 60% of its former strength.

According to the scientists involved, the next step is to work out how to perform multiple repairs on a single area. At present, the repair doesn’t contain the capillary system required to transport the healing materials, so this SHP is a one-time-only deal. But with advances in material technology progressing, we could see this problem solved sooner rather than later.

More on the wonder material is here.

Images via University of Illinois.