Grace by name, graceful by nature, the Gliding Robot ACE (GRACE) can travel a long way on little energy, and it may just help beach managers and environmental agencies keep an eye on oceans and inland waterways. She’s a bit like the robotic tuna, and the robotic sea turtle we’ve covered previously—only redder, and, perhaps, a little less animal-like.
The unmanned vehicle has two ways of moving. It glides, either by pumping in water and going diagonally to the bottom, or pumping out water and floating to the top. With a small battery, it can repeat the switching process, up and down, more than 200 times, thus having the ability to swim long distances. In addition, it has a flapping tail for added maneuverability.
"The exact distance it can go will depend on how many cycles of ascent and descent it does, and the depth of the water," says designer Xiaobo Tan, associate professor of electrical and computer engineering at Michigan State University.
Tan says GRACE is for sensing water quality and temperature, and security applications like tracking vessels around ports. "It could be used by people enforcing the rules, as well as people managing property, like beach managers and coast guards."
Last year, Tan’s team took the robot out on the Kalamazoo River, in Michigan, to test for long-term damage from Enbridge’s 2010 oil spill. Tan says Grace was effective in sensing pollution during three separate dives, finding more oil downstream than near the disaster site.
"The next step is looking at multiple robots co-operating with each other," he says. "They can form a network underwater and therefore be more efficient and effective in getting back information about the environment. You could have a swarm of these things, tens of them working together."