Glues are some of the most important substances in engineering today. The ideal adhesive should be strong yet resistant to wear and breaking down. A team of engineers at Purdue University looked to nature to create the perfect glue.
[Image Source: Purdue University/Jonathan Wilker]
The researchers studied shellfish that glue themselves in place to deter predators or resist moving during strong waters. Jonathan Wilker, professor of chemistry and materials engineering at Purdue, said nature solved our problems with wet bonding "eons ago."
"Mussels, barnacles, and oysters attach to rocks with apparent ease," he said. "In order to develop new materials able to bind within harsh environments, we made a biomimetic polymer that is modeled after the adhesive proteins of mussels."
Mussels use hair-like fibers to latch onto surfaces. Proteins in their adhesive contain an amino acid called DOPA which allows for the strong hold. The researchers took the compounds in DOPA (called catechols) and reconfigured them into a synthetic polymer.
The team then tested their new adhesive. Bond testing showed that the synthetic adhesive was 17 times stronger than the mussels' natural glue. The results surprised the researchers because science never comes close to surpassing nature.
"In biomimetics, where you try to make synthetic versions of natural materials and compounds, you almost never can achieve performance as good as the natural system," Wilker said.
The weaker natural adhesion can be attributed to mussels needing to move periodically. If their natural glue was too perfect, they would be stuck in one place for an entire lifetime, the team noted.
The team hopes to test the glue in real-world settings soon. If more research shows this innovation to be effective, it could lead to interesting new manufacturing techniques. It could become an important resource for underwater explorative teams needing to patch holes in vehicles. Or, it could simply be a nice way to patch a pool liner without having to drain and refill the entire pool.
You can read more about the team's findings in a research paper published in ACS Applied Materials and Interfaces.