Submersible Robotic Fishoplane Can Swim for Hundreds of Kilometers
As much as this may look like a fighter jet or spaceship, the folks at Xiaobo Tan's lab at Michigan State University are calling it a robotic fish. A robotic fish with a giant pair of wings that allow it to glide through the water with an incredible level of efficiency, giving this little guy a range of about 200 kilometers without having to be recharged. And why do we need a robot fish? BECAUSE IT'S A ROBOT FISH. Geez. And also because it can sniff out pollution for us.
The name of this robot fish is Grace, which stands for “Gliding Robot ACE.” We're not sure what "ACE" stands for, and we'd welcome any guesses. The gliding bit is the secret to this robot's efficiency: inside Grace's body/fuselage sits a battery pack mounted on a rail that runs from nose to tail. By shifting this relatively heavy bit back and forth along the rail, Grace changes her center of gravity, and pitches downward or upward. Combined with the a battery-powered pump that alters her buoyancy directly, she'll start to either ascend or descend in the water column, and as she does so, those wings convert the vertical motion into horizontal motion essentially for free. Here's a video:
The only time Grace is actually expending energy is when she switches from descent to ascent and vice versa: the rest of the time, her buoyancy is being converted into forward thrust by the wings. It's not very fast, and Grace isn't very maneuverable while moving this way, but she can go for a long, long time: Xiaobo Tan estimates that she's good for some 200 km on one single charge of her batteries. For those times that Grace needs to change direction or kick her speed up a notch, she's also got a powered tail that pushes her along just like a real fish.
Grace certainly isn't the first pollution-sniffing ocean glider; iRobot, for example, has been using its Seagliders very effectively for years. But Grace likely is among the smallest in this category, and the addition of a tail gives her the ability to work in shallower areas or in moving water (like in rivers and lakes) where gliding isn't ideal.
So what's Grace up to? Basically, she's equipped with a sensor package (like an oil detection system), and then she wanders around taking samples and wirelessly sending back data. In real world trials in the Kalamazoo River, Grace has proven to be quite effective, and she looks like she's a promising platform for all sort of research. And she'd be good for military operations, too, if they'd just outfit her with a couple torpedo tubes. Just a helpful suggestion, guys.