Researchers at ETH Zurich and the California Institute of Technology came together to work on a 3D-printed submarine that can navigate the water without an engine, a propellant or a power supply. The swimming robot does have its own paddles that are designed to react to changes in water temperature and behave quite similarly to the muscles of the body.
At present, a small prototype roughly three inches in size has been created and researchers must manually reset the robotic submarine. Even so, Kristina Shea of ETH Zurich notes ""the main takeaway from our work is that we have developed a new and promising means of propulsion that is fully 3D-printed, tuneable and works without an external power source." The researchers hope to continue developing the propulsion system, which could prove useful for a low-power vessel to explore the depths of the ocean.