Mantis shrimp

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The seemingly indestructible fists of the mantis shrimp can take a punch

Biomechanics, Mantis shrimp, materials science, Science / /

To find out how much force a mantis shrimp’s dactyl clubs can possibly withstand, the researchers tested live shrimp by having them strike a piezoelectric sensor like they would smash a shell. They also fired ultrasonic and hypersonic lasers at pieces of dactyl clubs from their specimens so they could see how the clubs defended against sound waves.

By tracking how sound waves propagated on the surface of the dactyl club, the researchers could determine which regions of the club diffused the most waves. It was the second layer, the impact surface, that handled the highest levels of stress. The periodic surface was almost as effective. Together, they made the dactyl clubs nearly immune to the stresses they generate.

There are few other examples that the protective structures of the mantis shrimp can be compared to. On the prey side, evidence has been found that the scales on some moths’ wings absorb sound waves from predatory bats to keep them from echolocation to find them.

Understanding how mantis shrimp defend themselves from extreme force could inspire new technology. The structures in their dactyl clubs could influence the designs of military and athletic protective gear in the future.

“Shrimp impacts contain frequencies in the ultrasonic range, which has led to shrimp-inspired solutions that point to ultrasonic filtering as a key [protective] mechanism,” the team said in the same study.

Maybe someday, a new bike helmet model might have been inspired by a creature that is no more than seven inches long but literally doesn’t crack under pressure.

Science, 2025.  DOI:  10.1126/science.adq7100

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This mantis shrimp-inspired robotic arm can crack an egg

biomimicry, biorobotics, Mantis shrimp, robotics, Science, soft robotics / /

This isn’t the first time scientists have looked to the mantis shrimp as an inspiration for robotics. In 2021, we reported on a Harvard researcher who developed a biomechanical model for the mantis shrimp’s mighty appendage and built a tiny robot to mimic that movement. What’s unusual in the mantis shrimp is that there is a one-millisecond delay between when the unlatching and the snapping action occurs.

The Harvard team identified four distinct striking phases and confirmed it’s the geometry of the mechanism that produces the rapid acceleration after the initial unlatching by the sclerites. The short delay may help reduce wear and tear of the latching mechanisms over repeated use.

New types of motion

The operating principle of the Hyperelastic Torque Reversal Mechanism (HeTRM) involves compressing an elastomeric joint until it reaches a critical point, where stored energy is instantaneously released.

The operating principle of the Hyperelastic Torque Reversal Mechanism (HeTRM) involves compressing an elastomeric joint until it reaches a critical point, where stored energy is instantaneously released. Credit: Science Robotics, 2025

Co-author Kyu-Jin Cho of Seoul National University became interested in soft robotics as a graduate student, when he participated in the RoboSoft Grand Challenge. Part of his research involved testing the strength of so-called “soft robotic manipulators,” a type often used in assembly lines for welding or painting, for example. He noticed some unintended deformations in the shape under applied force and realized that the underlying mechanism was similar to how the mantis shrimp punches or how fleas manage to jump so high and far relative to their size.

In fact, Cho’s team previously built a flea-inspired catapult mechanism for miniature jumping robots, using the Hyperelastic Torque Reversal Mechanism (HeTRM) his lab developed. Exploiting torque reversal usually involves incorporating complicated mechanical components. However, “I realized that applying [these] principles to soft robotics could enable the creation of new types of motion without complex mechanisms,” Cho said.

Now he’s built on that work to incorporate the HeTRM into a soft robotic arm that relies upon material properties rather than structural design. It’s basically a soft beam with alternating hyperelastic and rigid segments.

“Our robot is made of soft, stretchy materials, kind of like rubber,” said Cho. “Inside, it has a special part that stores energy and releases it all at once—BAM!—to make the robot move super fast. It works a bit like how a bent tree branch snaps back quickly or how a flea jumps really far. This robot can grab things like a hand, crawl across the floor, or even jump high, and it all happens just by pulling on a simple muscle.”

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