Scientists at MIT have found a solution to study fish and other marine life without disrupting their ecosystem. They developed a robotic fish that looks really natural, and sent it to inspect the Fiji coral reefs. This robot, called SoFi, is actually a vehicle that can travel on its own while looking as much as a fish as possible.
SoFi looks just like a real fish
Scientists knew they had to find a way to study underwater life without disturbing it, so they thought a robot fish might be the answer. This is how SoFi was born. They started with a soft muscle that imitates a fish tail. This muscle had a mechanism which could produce changes in pressure on the surface of the muscle, thus producing the undulating move of a tail.
“We developed a system that takes silicone elastomer and placed hollow cavities in such a way that can equally distribute pressure on the skin of the body,” said lead author Robert Katzschmann.
This system is based on pneumatic principles, which are quite common in this branch of robotics. The principles allow fish to be constantly moving while making no sounds while traveling through water. However, SoFi needed some guidance, so the scientists made use of sound properties differently.
Sound signals guide the robotic fish through water
Wi-Fi or Bluetooth signals were not a solution underwater, as they can barely propagate in this environment. This means the guiding signal should have been within a few feet from SoFi, risking the disturbance of other fish. However, sound faces no such limitations.
To guide the robotic fish, one researcher dives at a long distance from SoFi while using a waterproof Nintendo device that sends sounds signals. These high-pitched signals are successfully decoded by the robotic fish, and guide it towards the aquatic ecosystem. The whole process is described in a study published in the journal Science Robotics.
So far, they recorded a video with SoFi’s embedded camera. However, in the future, this mechanism can turn into an effective method to study underwater life and not disturb the fragile ecosystem.
Image source: Wikimedia Commons