Self-healing polymer uses sunlight to repair itself
arstechnica.com
arstechnica.com
One of my favorite professors here is doing research on self-healing metals. It's pretty sweet. They're using magnesium alloys for structural self-healing applications because magnesium exhibits a martensitic transformation (i.e it changes shape when you heat it). Oddly enough, martensitic metals are used in bra-supports so that they return to their original shape when washed, yet still give good support.
I love materials science.