Scientists at the University of North Carolina at Chapel Hill have created a type of putty that can transform over time because of an internal clock. The university team, led by professor Sergei Sheiko, tweaked the molecular structure of a conventional soft polymer to create a material that could be programmed to change shape.
Polymers feature molecules that lie next to each other and which can uncoil and slide past each other, making the material flexible. Only a small proportion of links between molecules in a polymer are permanent, which allows the material to return to its original form when stretched.
