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Polymers react to stress

2009; Nature Portfolio; Volume: 459; Issue: 7243 Linguagem: Inglês

10.1038/459045a

1476-4687

Christoph Weder,

Marine Biology and Environmental Chemistry

The latest polymers are chameleon-like: they change colour on deformation. The transduction mechanism underpinning this effect could be used to make polymers that respond in many other ways to mechanical stress. Biology is replete with materials systems that actively and functionally respond to mechanical stimuli and thereby enable physiological processes such as the sense of touch, hearing or the growth of tissue and bone. In contrast, exposing polymers to large stresses tends to result in covalent bond rupture and hence damage or failure. Davis et al. now demonstrate that synthetic materials can be rationally designed to ensure that mechanical stress alters their properties in a useful manner. This is realized by incorporating a chemical group that responds to mechanical stress by changing its colour to red as it undergoes a ring-opening reaction, enabling the team to directly monitor the accumulation of plastic deformation. The principles underpinning this work should enable the development of other force-responsive chemical groups that could impart synthetic materials with desirable functionalities ranging from damage sensing to fully regenerative self-healing.