The line between man and machine continues to be burred, and next-gen plastics are taking it a step further. A team of researchers at the National Meeting & Exposition of the American Chemical Society described a type of plastics that would "bleed" when scratched, punctured or otherwise "wounded" and would then proceed to repair itself.
ACS has more on a polymer that, like human skin, would have the ability to self-repair:
“Mother Nature has endowed all kinds of biological systems with the ability to repair themselves,” explained Professor Marek W. Urban, Ph.D., who reported on the research. “Some we can see, like the skin healing and new bark forming in cuts on a tree trunk. Some are invisible, but help keep us alive and healthy, like the self-repair system that DNA uses to fix genetic damage to genes. Our new plastic tries to mimic nature, issuing a red signal when damaged and then renewing itself when exposed to visible light, temperature or pH changes.”
Urban, who is with the University of Southern Mississippi in Hattiesburg foresees a wide range of potential applications for plastic with warn-and-self-repair capabilities. Scratches in automobile fenders, for instance, might be repaired by simply exposing the fender to intense light. Critical structural parts in aircraft might warn of damage by turning red along cracks so that engineers could decide whether to shine the light and heal the damage or undertake a complete replacement of the component. And there could be a range of applications in battlefield weapons systems.
ACS goes on to report that as of right now there are two strategies to develop self-healing polymers. One depends on compounds with "healing" properties being released when a plastic becomes "injured." Others rely on exposure to a certain type of light to catalyze the reaction. Urban believes those healing through light exposure are more beneficial as they can repair multiple times, whereas those relying on compounds that can heal only once.
Discovery News reports that this is the first case of a polymer that changes color when damaged and also heals itself. This color change, according to University of Fribourg scientist Christoph Weder who showed in a paper last year that UV light could heal certain polymers, is crucial for indicating where a plastic may need light exposure. Discovery News reports Weder saying, “It shows you where the defect is and the system can then be healed.”
Urban's research was partially funded by the Department of Defense.
[H/T Popular Science]