A new tuna robot could lead to more agile and efficient underwater drones

Robots that can swim underwater are nothing new. For instance, Carnegie Mellon fitted its famous snakebot with turbines and thrusters earlier this year to give it aquatic capabilities. But few can do so with the grace, speed and effortlessness of a real-life fish. And it's not that scientists have avoided trying to create a robot that can do just that, but the exact way fish swim faster or slower is something that has proved elusive. Marine biologists have known for a while that the secret lies somewhere in the way they can alter the rigidity of their tails.