Researchers from the Fraunhofer Institute of Manufacturing Engineering have created a propulsion system which is closely based upon how an octopod naturally propels itself. This system was built through a 3D printer in a single step.
Octopods make use of their natural propulsion technique when escaping prey or moving at high speeds. They do so by squirting water using sphincter muscles and creating a jet to propel them in the opposite direction. The scientists replicated this by creating actuators, that is, four elastomer balls that build propulsion by pumping water through inner mechanical workings.
The water is sucked into the actuator through an opening and a hydraulic piston powered by a motor pump contracts the structure like a muscle and pushes water out. The entire system was created in a 3D printer by the fused deposition modelling generative process (FDM); a process wherein the plastic used is heated, liquefied and made into filaments which are then applied in layers to create the complex model.
To withstand pressure and heat, the scientists made use of thermoplastics and created a system which they feel would greatly benefit jet skis, divers and smaller ships or boats and would also be a clean, cheap mechanism which is safe for marine life.