Scientists have designed and developed a robotic shrimp that's eerily similar to the pistol shrimp. The pistol shrimp is just a few inches in length and has a massive claw that is so strong it can knock out its prey with the shockwave when the claw snaps. Once the claws come together, bubbles develop, collapse and shoot out a bolt of plasma that creates a flash of light with temperatures reaching 8,000 degrees Fahrenheit. Researchers explain how they designed a robotic claw inspired from the pistol shrimp's claw to create plasma. The robotic claw could be useful tool for underwater purposes.


How they propose to create some biomimicry. (Image Credit: Xin Tang and David Staack)


The pistol shrimp uses its claw to hunt and communicate with small snaps, measuring 210-decibel units. In comparison, an actual pistol shot measures 150 decibels. Some species also use the plasma to create a shelter out of coral reef, causing high noise interference that can affect sonar.


Texas A&M engineer David Staack and his team used an exoskeleton to create a cast of the claw. He scanned the claw into a 3D model, sent it off to Shapeways, the 3D printing company, who then gave him a plastic version of the pistol shrimp's plasma gun. Staack's version of the claw is designed so that the top half spins quickly on a spring-loaded rod that creates the right amount of force to snap the plunger into its socket. This creates a high-velocity stream of water, creating a cavitation bubble, which is large and has low-pressure but then begins to collapse.


During experiments, researchers used high-speed cameras to watch the jet of water blast out from the claw. Images of the shockwaves were also captured with the flash of light as the plasma is created. Using the claw to create plasma is 10 times more effective than other methods, like lasers and plasma arc welding.

Staack's claw will also need more developmental work to fit to scale. It may be more efficient than that, however, because researchers do not need to follow the structure and biological requirements of the pistol shrimp for it to work effectively. The upper part of the claw could be trimmed away. The pistol shrimp's claw is massive because it holds the muscles needed to have control of the limb. The robotic claw doesn't need that space.


Researchers also have the task of using morphologies from different species of pistol claw to draw inspiration from and tweak their own robot claw. Which, may allow researchers to use the design and idea of a robot claw in other fields as well. Claw-generated plasmas could be used to drill through rocks. It can also be used for water purification by breaking up the watr into its other elements, forming a peroxide. Peroxides would then clean up any contaminants in the water which can be very useful in municipal water management.


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