U.S. Navy Developing Hagfish Slime Defenses
A team of U.S. Navy scientists and engineers is synthesizing the slime exuded by hagfish with the aim of using it for ballistics protection, firefighting, anti-fouling, diver protection or anti-shark spray.
Biochemist Dr Josh Kogot and materials engineer Dr Ryan Kincer of Naval Surface Warfare Center, Panama City Division, have produced a synthetic component of hagfish slime in Escherichia coli bacteria.
Pacific hagfish, also known as slime eels, are bottom-dwelling scavengers which live on the ocean floor. They can secrete slime to protect themselves by obstructing the gills of predators which come into contact with the slime.
According to Kincer, hagfish slime consists of 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,” said Kincer. “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. Studies have shown the hagfish secretion can expand up to 10,000 times its initial volume.”
The hagfish slime thread has been compared to spider silk. Both are natural, renewable materials which could one day replace synthetic products derived from petroleum-based precursors. Kogot said the slime thread has comparable mechanical properties to Kevlar, a synthetic fiber used as a reinforcing agent for rubber products and protective gear.
“The possibilities are endless,” said Kogot. “Our goal is to produce a substance that can act as non-lethal and non-kinetic defense to protect the warfighter.”
The researchers are developing ways to increase the slime's surface attachment capability, potential delivery systems and enhanced stability in various environments.