US navy harnesses power of eel slime

An artificial biomaterial, based on the slime secreted by the Pacific Hagfish (also known as the slime eel) could have a range of applications in the marine defence sector.

eel slime
Hagfish slime has a number of useful properties. Image Credit: DirtSailor2003 (via Flickr)

Developed by a team of researchers from the US Navy’s Naval Surface Warfare Center in Panama City, Florida the material mimics the behaviour of the slime, which the fish secretes in order to obstruct the gills of predators.

The group, led by Biochemist Dr Josh Kogot and Materials Engineer Dr Ryan Kincer believe that the material – which has properties comparable to Kevlar – could be used by the navy for ballistics protection, anti-fouling and even as an anti-shark spray for divers.

According to Kincer, hagfish slime owes its properties to two protein-based components: a thread and a mucin.

“The coiled up thread behaves like a spring and quickly unravels upon contact with water due to stored energy,” he explained. “The mucin binds to water and constrains the flow between the micro channels created by the thread dispersion. The interaction between the thread, mucin, and seawater creates a three-dimensional, viscoelastic network. Over time, the thread begins to collapse on itself, causing the slime to slowly dissipate.”

During synthetic recreation, alpha and gamma proteins were produced using E.coli bacteria. These proteins were then combined together and rapidly assembled in a crosslinking solution. A sample of natural and synthetic hagfish threads were compared using a scanning electron microscope to visually confirm the production of the synthetic threads.

“Researchers have called the hagfish slime one of the most unique biomaterials known,” said Kincer. “For the US Navy to have its hands on it or a material that acts similar would be beneficial. From a tactical standpoint, it would be interesting to have a material that can change the properties of the water at dilute concentrations in a matter of seconds.”

The team is now exploring ways to increase the slime’s surface attachment capability, as well as potential delivery systems.