See How Nature Inspired This DIY Robotic Fish That Actually Swims
By combining a few servo motors and an Arduino Nano, YouTuber mcp was able to create a robot that swims like a real fish
How do fish swim?
Over the course of thousands to millions of years, nature has selected traits which allow certain fish to swim through the ocean at extreme speeds. Some of these include slick skin covered in scales that allows water to effortlessly glide past, while other might involve powerful muscles in the body and tail for generating forward momentum. By applying these characteristics to a robot of his own (known as biomimicry), the maker mcp on YouTube was able to create a DIY Robotic Fish that can swim.
His design takes inspiration from the way fish such as Tuna flap their tails side to side to create strong currents behind them to propel themselves forward. But instead of using soft muscle tissue, mcp opted for a few servo motors instead.
Constructing the body
The "chassis" of the fish, or its spine, was created by 3D printing a series of vertebrae that each contain a mini servo motor that can move in a single axis. Once all of these were chained together, his fish could move with the help of several coins for balancing purposes.
Sensing obstacles
Swimming around in a pool is fine on its own, but what happens when the fish encounters the edge or some other obstacle? It is for this reason that mcp added two infrared emitter/receiver pairs on the front of the robot to act like eyes and see when it gets too close to an object. If the sensors alert the Arduino Nano microcontroller to something in front, the servos can be instructed to favor one direction and thus steer the fish away safely.
Going for a dip
This DIY Robotic Fish project was first tested in a small bathtub after it had been fitted with a latex skin for water-proofing and to allow the fish to glide more easily through the water. Next, mcp added some small decorations such as a couple of bands to mimic natural coloring and some paint around the eyes to make them more true-to-life.
As seen in the video below, this robotic fish bears a striking resemblance to one made of flesh and bone, and its ability to guide itself away from objects causes this project to become even better.