Learning from mussels to stretch with strength
Marine mussels inspire a new way to make stretchy polymers that are stiff, strong, and extensible, just published in Science.
Elastomers constitute a wide range of polymer-based materials from tire rubber and wet suit Neoprene to Lycra clothing and Silicone — that are valued for their ability to flex and stretch without breaking and return to their original form.
One challenge with such materials is that making them stronger usually involves the trade-off of making them more brittle. That’s because structurally, elastomers are rather shapeless networks of polymer strands (often compared to a bundle of disorganized spaghetti noodles) held together by a few chemical cross-links. Strengthening a polymer requires increasing the density of cross-links between the strands by creating more such links. That causes the elastomer’s strands to resist stretching away from each other, giving the material a more organized structure, but also making it stiffer and more prone to failure.
Inspired by the tough, flexible polymeric byssal threads that marine mussels use to secure themselves to surfaces in the rugged intertidal zone, we developed a method for overcoming the inherent trade-off between strength and flexibility in elastomeric polymers. An article describing the research, titled “Toughening elastomers using mussel-inspired iron-catechol complexes,” lead-authored by postdoctoral researcher Emmanouela Filippidi and PhD student Thomas R. Cristiani, appears in the October 27th issue of the journal Science.
