Octopus inspires 3D printed propulsion system
Researchers from Germany's Fraunhofer Institute have taken inspiration from the octopus to create a silent propulsion system for boats and submarines.
When frightened, octopuses escape by ingesting sea water and jetting it out of their body in a high powered stream. This allows them to move quickly and quietly, and in any direction they wish.
The Fraunhofer system consists of four elastomer balls (actuators), each with a hydraulic piston inside. Water is sucked into each ball through an opening and a hydraulic piston contracts an integrated cable structure like a muscle.
In this way, it pushes the water out of the 20 x 6cm ball. A motor pump moves the hydraulic piston.
"Our underwater actuator is well suited for maneuvering small boats," said Fraunhofer engineer Andreas Fischer. "It can also be used as a floating aid for water sport devices such as jet skis, surf boards, or scooters that pull divers into deep water."
According to Fischer, the whole apparatus can be fabricated in one step, using a 3D printer. The researchers say a commercial version of the technology would allow for fast and quieter travel. There would also be no danger of sea creatures being cut by propellers.
