Two characteristics that an underwater robot should have are speed and manoeuvrability. These qualities are present in sea turtles. Designing a robot like a sea turtle also allows scientists to place the batteries and electronic components in the shell. ETH Zurich and ARROWS project have already created their lot of turtle bots and recently, National University of Singapore has stepped into the competition and came up with a robot that is capable of charging itself while being at sea.
The team lead by Professor S.K. Panda which is busy developing the turtle robot, has previously created robotic fishes of various types as well. The turtle-bot swims and can execute sharp turn at high speed like a real turtle, using the selective paddling motions of their front and rear flippers. Using this form of locomotion, they can also dive and ascent without taking on or releasing ballast. As it does not require ballast tanks or pumps, the turtle robot is smaller, lighter and much more energy efficient that it would have been otherwise. That lack of a ballast system could consecutively allow it to take on larger payloads than comparably-sized robots.
The robot is also able to charge its battery pack using the integrated solar panels by surfacing during a mission. Hence its missions are not limited to the duration one battery pack might provide. According to the researchers, it can also charge its batteries by settling in one spot on the sea floor, and then harnessing the power of underwater currents.
Such battery charging system has already been utilized by a spherical robot previously developed by the team, which takes its place in the water as the passing water spins a set of built-in rotor blades connected to a dynamo-type generator.
The turtle robot can be used to accomplish tasks like surveillance, detection of hazardous waste and monitoring the water quality. It could operate alone on solo missions, although team missions can also be a possibility, in which the robots can communicate with each other while collaborating on bigger tasks.