MIT engineers have created a new stronger waterproof glue inspired by Inspired by natural adhesives secreted by shellfishes like mussels and barnacles, that can be used to repair ships and even heal wounds and surgical incision. These shellfish have sticky proteins which help them to survive in underwater conditions by allowing them to cling to rocks or ship hulls.
If we typically talk about mussels, these have a structure termed as ‘beard’ which is scientifically known as byssus. This is used by the mussel in attaching itself to surfaces with an aid of secreted adhesive cement. Mussel proteins are basically of two types-mussel foot protein 3 and mussel foot protein 5.
To create their new waterproof adhesives, the researchers at Massachusetts Institute of Technology engineered bacteria to produce a hybrid material that incorporates two components i.e. naturally stick mussel protein and bacterial protein which is found in biofilms. These are the slime layers formed by bacteria growing on a surface. This combination is considered to be better than sole mussel, for it forms a stronger underwater adhesive. Researchers believe that this is the biggest genetically inspired, protein-based underwater adhesive, reported to date.
“The ultimate goal for us is to set up a platform where we can start building materials that combine multiple different functional domains together and to see if that gives us better material performance”, said Timothy Lu, an associate professor of biological engineering and electrical engineering and computer science (EECS).
The team engineered bacteria to form two different foot proteins combined with bacterial proteins and this structure is called as curli fibers. These are the fibrous proteins that can assimilate together and form larger and complex mashes.
After purifying these proteins from bacteria, scientists let them incubate and form denser structures. The resulting structure has been designed that can bind in dry and wet conditions.
They tested the adhesives using the atomic force microscopy, a technique that probes the surface of a sample using a needle tip.
“The result is a powerful wet adhesive with independently functioning absorptive and cohesive moieties”, says Herbert Waite, a professor of chemistry and biochemistry at the University of California, who was not even the part of the research. “The work is very creative, rigorous and through”.