Mantis shrimp’s killer punch inspires new armour

1 Jun 2016

There are many fascinating elements to a mantis shrimp, but its powerful punch has captured the imagination of researchers in the US.

Mantis shrimps are amazing, armed with eyes that see colours we couldn’t even dream of, and a punch that can crack through some of the toughest shells in the ocean.

It is the latter capability that interested researchers in the US who are trying to develop new forms of body armour, helmets and car parts by replicating how mantis shrimp smash up their prey.

Not all mantis shrimps smash up prey, actually. There are also ‘spearers’ that stab at sea creatures not protected by hard shells.

But that’s not much use when it comes to body armour design, so the ‘smashers’ are the celebrities for now, with the ability to pulverise shells with a punch that accelerates at 10,000g, impacting at speeds similar to a .22 calibre bullet.

The weapons used to impart this force are called dactyl clubs, which have been the subject of eight years of research at the University of California, Riverside.

David Kalius and his team have been constantly investigating how to create new, powerful composites, with a 2012 paper published by the team highlighting specific regions of the dactyl used to smash up shells.

This included an interior, ‘periodic’ region that absorbs energy and filters out damaging ‘shear’ waves that are created under stress.

Now, after partnering up with a team from Purdue University, the exterior of the club has been profiled in a new paper published in Advanced Materials.

Called the ‘impact’ region of the club, it consists of the same mineral found in human bone, compacting all the organic fibre inside into a “herringbone structure”.

This is key, claims Kisailus’ team, as it allows the mantis shrimp to protect itself at one end, while destroying prey at the other.

Nicholas Yaraghi – a member of Kisailus’ group – said this is the first time the unique herringbone structure has been observed in nature, saying the discovery is “exciting to reveal”.

The outer regions of the impact region were found to contain elements that the researchers think spreads the stress around, saving the club from breaking.

The next stage is to incorporate some of the features found in the herringbone structure into existing composites.

Mantis shrimp image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic