Today's KNOWLEDGE Share : Mantis Shrimp Pack a Punch With the Force of a Bullet

Today's KNOWLEDGE Share

Mantis Shrimp Pack a Punch With the Force of a Bullet and They Don’t Get Hurt.

Mantis shrimp are powerful little crustaceans: With a single, strong punch, they can smash a shell with the force of a .22 caliber bullet, unleash a shockwave and even crack aquarium glass—all without hurting themselves.

Now, scientists have discovered how the colorful invertebrates use the power of physics as a shield. Their punching fist, called a dactyl club, has a protective structure with multiple layers that the team says might one day inspire impact-resistant gear for humans. Their findings were published in the journal Science last week.

“To repeatedly execute these high-impact strikes, the mantis shrimp’s dactyl club must have a robust protection mechanism to prevent self-damage,” explains Horacio Espinosa, an engineer at Northwestern University who co-led the study, in a statement. We found it uses phononic mechanisms structures that selectively filter stress waves.This enables the shrimp to preserve its striking ability over multiple impacts and prevent soft tissue damage.

The team of researchers tested a hypothesis that the peacock mantis shrimp’s resilience comes from the structure of its dactyl clubs. The outer part of the club is covered in layers of mineralized fibers that form a V-shaped herringbone pattern, giving it resistance. Underneath, corkscrew like bundles of fibers form what’s called a Bouligand structure, where the fibers fan out in different directions.

In 2015, researchers proposed that the Bouligand structure in the lower layer could filter out certain high-frequency shockwaves from the punch, preventing the damaging vibrations from traveling back into the mantis shrimp’s body. But scientists hadn’t proven it in the lab.It was mostly theoretical calculations.

So, the Northwestern researchers conducted various experiments to confirm the idea. They used lasers to analyze how stress waves travel through the mantis shrimp’s club and used high-frequency pulses to peer into the inner workings of the armor’s microstructure.

Their work revealed that the outer layer of herringbone fibers helps the club resist cracking from the strike, while the inner Bouligand structure can selectively absorb high-frequency stress waves that might otherwise harm the rest of the creature’s limb.

The findings highlight the potential of exploiting these natural designs for technological applications. The structure could inspire new designs for protective military and sports equipment, as well as impact-resistant coatings & improved materials for the aerospace industry.

While the study used 2D models of the shockwaves, more complex, 3D simulations are needed to fully capture how the club’s structure works. Designing aquatic experiments with state-of-the-art instrumentation would allow us to investigate how phononic properties function in submerged conditions.”

source:smithsonianmag.com

video source:You Tube

https://youtu.be/E0Li1k5hGBE