This miniature robot imitates the punch of a mantis shrimp


Mantis Shrimp Has one of the most powerful and ultra-fast punches in nature-it is compatible with Force generated Use 0.22 caliber bullets. This makes this organism an attractive research object for scientists eager to learn more about biomechanics. Among other uses, it can lead to small robots capable of equally fast and powerful movements. Now, a group of researchers at Harvard University has proposed a new biomechanical model for the mantis shrimp’s body. Powerful appendageAnd built a miniature robot to imitate this movement, according to A recent paper published in Proceedings of the National Academy of Sciences.

“We are fascinated by so many extraordinary behaviors that we see in nature, especially when these behaviors reach or exceed the level that man-made devices can achieve,” Senior author Robert Wood said, Robotics expert at Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS). “For example, the attack speed and power of the mantis shrimp are the result of complex underlying mechanisms. By building a robot model of the mantis shrimp impacting its appendages, we can study these mechanisms in unprecedented detail.”

Wood’s research group made headlines when it was built a few years ago Robot bee, A miniature robot that can fly partially unfettered. The ultimate goal of the plan is to build a group of micro-interconnected robots that can continue to fly without cords-given the size of the insects, it changes various forces at work, which is a major technical challenge. In 2019, Wood Group Announced its achievements The lightest insect-level robot to date has achieved continuous, unfettered flight-an improved version called RoboBee X-Wing. (Kenny Brewer, writing in nature, Described it As a “masterpiece of system design and engineering.”)

Now, Wood’s team turned their attention to the biomechanics of the mantis shrimp knockout punch.As We have reported Before, Mantis Shrimp There are many kinds; there are about 450 known species. But they can generally be divided into two types: one that stabs the prey with a spear-like appendage (“spear gun”) and smashes the prey with a large, round hammer-like claw (“the raptor appendix”). These attack speeds are so fast. They are fast (up to 23 meters per second, or 51 mph) and powerful. They usually produce cavitation bubbles in the water, produce shock waves that can be used as subsequent attacks, stun and sometimes kill prey. Sometimes, impact It even produces sonoluminescence, which makes the cavitation bubbles produce short flashes when they collapse.

according to A 2018 studyThe secret of a powerful punch does not seem to come from the huge muscles, but from the spring anatomy of the shrimp arm, similar to a bow and arrow or a mousetrap. The muscles of the shrimp pull the saddle-shaped structure on the arm, causing it to bend and store potential energy, which is released with the swing of the rod-shaped claws. It is essentially a latch-like mechanism (technically speaking, latch-mediated spring drive, or LaMSA), a small structure in the tendon called the sclera, which acts as a latch.

This is well understood. There are several other small creatures that can produce ultra-fast movements through a similar locking mechanism: for example, the legs of frogs and the tongue of chameleons, the mandibles of trap jaw ants and exploding plant seeds. But for many years Biologists who have been studying these mechanisms have noticed something unusual about the mantis shrimp-there is a 1 millisecond delay between unlocking and breaking.

“When you observe the impact process on a super high-speed camera, there is a time delay between the release of the bone fragments and the firing of the appendages,” Co-first author Nak-seung (Patrick) Hyun says, SEAS postdoctoral fellow. “It’s as if a mouse triggered a mousetrap, but it didn’t catch it immediately, but there was a noticeable delay before it was caught. Obviously there is another mechanism to fix the attachment in place, but no one can understand the other through analysis. How the mechanism works.”


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