Air bubbles are often used by underwater mantis shrimps to destroy rocks and attack other creatures. It is all about cavitation: when an air bubble emitted by the claws collapses, it generates hydraulic and sound waves producing a destructive effect.
Scientists have recently decided to replicate this principle. To do this, they carefully studied the claws structure of this small but very dangerous creature, and printed out the resulting mockup model on a 3D printer.
The form of the claws copied to the minutest detail allows them to create a powerful stream of water that produces cavitation bubbles. They travel for a mere 4 cm, but reach the speed of 70 km/h. The collision with the target produces noise of 218 dB, plasma of 4700 degrees Celsius and pressure of 80 kPA.
There are plans to use this know-how to build a powerful underwater gun, which can find many applications including in construction.