Purdue University researchers are studying hundreds of mussels and oysters growing in a lab to learn about natural adhesives for generating synthetic versions to use in electronics, vehicles and construction.
Their work is described in a Feb. 18 article in the Journal of the American Chemical Society.
To make adhesives tougher, the team’s approach is to first make such materials weaker. “We have been using inspiration from sea creatures to develop several new adhesives,” said Jonathan Wilker, a professor at Purdue in chemistry and materials engineering, who leads the team.
The researchers added chemical bonds to the glue that are broken easily. When pressure or stress is applied to the glue, these “sacrificial” bonds are designed to absorb energy and break apart while the rest of the larger adhesive system remains intact.
Wilker explained that the idea is similar to how brick walls are made of bricks offset from one another. Masons building a wall stagger the bricks and cement “so that a crack does not shoot right down through the cement lines,” he said. “A crack hits the middle of a brick and the forces get spread out toward both sides, eventually decreasing to the point that the wall stays intact.”
In similar fashion, Purdue researchers added weak bonds within the adhesive so that mechanical forces and growing cracks lose energy by breaking these bonds instead of becoming a larger fracture. “The idea is to manage how energy moves through the material,” he said.
The idea has been tested on several types of bonds, and the best ones were neither too weak nor too strong.
The mussels and oysters play a part by contributing proteins that they use for attaching to rocks. Studying the natural adhesives, the team has learned to generate synthetic versions. They have patented several of their toxin-free adhesive systems and are looking for partners to continue developing the technology. Interested parties should contact Joseph Kasper of Purdue’s Office of Technology Commercialization at [email protected].