[Festo] have come up with yet another amazing robot, a swimming one this time with an elegant propulsion mechanism. They call it the BionicFinWave. Two fins on either side almost a body-length long create a wave which pushes water backward, making the robot move forward. It’s modeled after such fish as the cuttlefish and the Nile perch.
What was their elegant solution for making the fins undulate? Nine lever arms are attached to each fin. Those lever arms are controlled by two crankshafts which extend from the front of the body to the rear, one for each side. A servo motor then turns each crankshaft. Since the crankshafts are independent, that means each fin operates independently. This allows for turning by having one fin move faster than the other. A third motor in the head flexes the body, causing the robot to swim up or down.
There’s also a pressure sensor and an ultrasonic sensor in the head for depth control and avoiding objects and walls. While these allow it to swim autonomously in its acrylic, tubular track, there is wireless communication for recording sensor data. Watch it in the video below as it effortlessly swims around its track.
[Festo] has created a lot of these marvels over the years. We’ve previously covered their bionic hopping kangaroo (we kid you not), their robot ants with circuitry printed on their exoskeleton, and perhaps the most realistic flapping robotic bird ever made.