The researchers started by creating a 3D-printed replica of the shrimp's claw, which includes a top half that cocks back like a gun, and a plunger that smacks into a socket in the bottom half. The human-made version relies on a top half that spins quickly on a spring-loaded rod, producing the force needed to have the plunger shoot into the socket. In both cases, the animal and the robot create a rapid stream of water that leads to a cavitation bubble -- the collapse of that bubble produces the plasma and the subsequent shockwave.

There's a lot of refinement necessary before you could see underwater robots that throw a mean hook. A design that moves beyond imitating the shrimp could be more powerful. You might see plenty of uses in the long run, mind you. It could be strong enough to drill through rock, or to purify water by breaking it down into peroxides. While it's a forceful blow, it could ultimately prove more useful for enhancing lives than destroying them.