Shrimp gun, aka shrimp snapping, is a strange contradiction. Only a few centimeters long, it carries one claw of proportional size, and another massive, crashing with such force, the waves of shock from the victim. When two pieces of claw come together, bubbles form and then collapse rapidly, firing a plasma ball which in turn produces a flash of light and temperatures of 8,000 degrees Celsius. It is true – an underwater creature that fits in the palm of your hand can, by jumping a claw, kiss the hot bubbles.
Now scientists are learning how to use this powerful force themselves. Today in the diary The progress of science, The researchers detail how they modeled a robotic claw after the gun of the plasma gun to produce their own plasma. It can find a variety of underwater uses, once scientists have sharpened the version of one of the strangest inventions of evolution.
If any shrimps gun has a hammer and a plasma explosion, the whole world does look like a nail. She uses her claw to hunt, sure, but also communicate with short whips that measure 210 dB. (An actual gun shot produces around 150 decibels). Some species even use plasma blasts to carve the pieces of a reef for a receiver. The result is a sea floor that is so noisy it can actually interfere with sonar.
Texas A & M Mechanical Engineer David Stack realized that versatility might be useful for humans as well. His team started by getting ahold of some live shrimp gun. Like other arthropods, these animals are copied from time to time, shedding their outer skeletons as they grow. These skeletons gave Stack a small claw of the claw, which he scanned to form a detailed three-dimensional model. He sent this to Pauice, the commercial printing service of 3D, and returned to the plastic version of the plasma gun of the gun pistol.
This allowed Stack to experiment with the unique structure of the organ. The upper half of the claw, where the shrimp throws back locks, including "piston", which is slammed into the "socket" at the bottom of the claw. This creates a rapid flow of water that produces bubbles, also known in this condition as cavitation.
"It reminded us of a mousetrap," he says. "So we really did a few experiments where we put some mouse traps under water just to see how quickly the little arm would turn around when they turned it on." We took the idea of the rat trap and used it as a way to close the sulfur.
In Stack's version of the claw, its upper half rotates quickly on a loaded rod in the spring, creating enough power to plunge the plunger into the socket. This produces a high-speed current of water which in turn generates a cavitation bubble, which initially at relatively low pressure is greater. But then it begins to collapse.
"The water is pushed in and pushes in and pushes in and you get very high pressures and temperatures," he adds. The temperatures are so high, in fact, that they form a light-emitting plasma, which can be seen even when the shrimp and the gun pinches its claw. "When she tries to push the water back out, she sends a shock wave." That's how cancer knocks its prey in nature.
In the lab, the researchers used high-speed cameras to see the water jet burst from their claw. They also photographed the waves of shock resulting from it, capturing the flash of light as plasma shapes.
Shrimp gun does not have a monopoly on plasma generation underwater. People weld underwater using plasma, known as plasma arc welding, which produces intense heat. The researchers can also make plasma water with lasers. The problem is that these measures are ineffective. Using a claw to create a plasma is 10 times more efficient than those previously studied methods, according to Stack. It will, though, require more development to size.
It may be even more effective that researchers should not faithfully follow the biology of the shrimp and the gun. In fact, Stack realized they could cut the size of the top of the claw. In the actual shrimps gun, it is bulbous because it holds the muscles required to activate the organ. But this robotic version is not limited to this biology.
"Replication of what the animal has done is the first step," says Rich Crane, a biologist at Stanford University who helped develop the Ninth Abbott, a device that replicates the strike of Mantis Shrimp, which produces cavitation bubbles. "So you can look at it and understand, yes, I do not need a huge muscle, so I can cut that part so you can engineer a better system."
Researchers may even want to look back at nature ways to tweak the system. Hundreds of species of shrimp and gun are diving away in the sea, each with its own custom claw. It's even people Inside Sex changes in their morphology.
"The platform for evolution, the only reason we have shrimp of all different varieties today, is because of a personal variation," says biologist Duke Sheila Patek, who studied the strike of Mantis shrimps. So while researchers can make their changes to their clone robot, they can also draw inspiration from the inherent diversity of the shrimps and gun to play with claw morphologies other than the one they originally printed 3D.
This diversity may one day see a device inspired by a shrimp gun used in a variety of areas. One approach would be to use a plasma created plasma to drill through a rock, as a crab makes in the wild to make a house on a reef. Or you can use a water purification system by breaking the water into its component parts, which creates oxygen. "These peroxides can then attack organic pollutants in water," Stack says. "If you think about cleaning urban water or cleaning sewage, efficiency becomes very important."
And so the shrimp and gun finds a few more nails.
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