Engineers inspired by octopus silent propulsion system

A team of German scientists develop a silent propulsion system for boats and submarines based on the natural movement of octopuses. 

In 1870 Jules Verne described the Nautilus as "a masterpiece containing masterpieces". Verne, an advanced mind for his era, was no stranger to coming up with fictitious ideas that will later on become a reality - From the Earth to the Moon, 20,00 Leagues Under the Sea. A team of German scientist from the Fraunhofer Institute have recently unveiled a Vernesque nautical propulsion system based on the cephalopods rocketry movement. Octopuses, like other cephalopods, can move around by using its tentacles as legs; but when a rapid movement is required, they can eject a jet of water from their mantle through the siphon for a short burst in order to escape from any peril.

This development of natural evolution has been the inspiration behind the latest water propulsion system designed at the Fraunhofer Institute for Manufacturing Engineering and Automation in Stuttgart, Germany. Among the many novelties in this prototype, is the possibility of being 3D printed in a single step. A set of four artificial mantles (elastic balls) replicate the cephalopods movement by filling up with water through a recirculation valve and then internal cables work as the muscle fibers by contracting when activated by the piston, ejecting the fluid through the steerable siphon. The prototype currently fits in a medium fish tank, but it can be scaled up to reproduce elastic mantles of up to two meters in diameter. This would allow for boats, submarines and recreational ships to be propelled by this system. The innovation has many benefits when compared with the current bladed propeller methods: 1. It represents zero danger to sea life because it has no bladed parts that can cut and kill animal life. 2. It does not need any rotating part, therefore it is much more silent than any diesel engine or gas turbine. This could potentially revolutionize stealth vessels. 3. The reduced complexity of the system makes it easier and cheaper to maintain due to the lack of many rotating parts. There are currently other similar ideas to the replication of the octopus propulsion system, but this is the first one fully built with a 3D printer. As of now, the invention is still in its prototype stage, and it will take years before this revolutionary system is present in the market. However, as more players join the competition, the development towards a certified product will move faster.