Developed in collaboration with the University of Virginia and Harvard University, a robot fish is a combination of biological data and robotics. Modeled specifically after the Yellowfin tuna and the related Atlantic mackerel, the artificial fish, called “Tunabot” can swim as fast as real fish.
The Tunabot is built from 3D-printed steel and resin, covered in a stretchy plastic skin. It mimics an adolescent tuna, but without any fins other than the tail. The robotic fish is 25.5 centimeters long, 4.9 centimeters thick and 6.8 centimeters high – this makes it a lot smaller than a real tuna. The skin of the robot tuna is around 1.5 millimeters thick.
The researchers hung the Tunabot in a bowl of water to test its swimming behavior. The fish was able to move its tail back and forth with a remarkably high frequency of 15 Hz – 15 times per second. It can achieve a speed of 4 times its height (as biologists express that) per second, about 1 meter per second.
It is not quite as fast as tuna (the real fish) but far faster than most other swimming robots or robotics fish that we have seen in recent years.
This is an impressive performance, but at this speed, the robot fish is not swimming at its most efficient. With a battery charge of 10 watt-hours, the fish could swim at a speed of 0.4 m/second (1.3 ft) for a distance of about 9 km (5.6 miles). At its top speed of 1 meter per second, the range would drop to around 4 km (2.5 miles).
Although the Tunabot is one of the fastest robot fish to date, the researchers do not mention applications in their paper. But it is quite conceivable that scientists want to take underwater measurements at different locations in an area. For this, the Tunabot (or a successor) should have small sensors on board. The underwater robot also seems suitable for taking water samples at locations that are miles apart.