As the researchers led by Li Wen of Beihang University in China report in the journal Science Robotics, the robot has a suction disc modeled after a remora fish. These are fish that attach themselves to sharks or other large fish with the help of a suction plate in order to use them as a kind of cab.

The robot uses this device to attach itself to wet or dry moving objects, significantly reducing its power consumption. In fact, the 3D-printed robot consumes nearly twenty times less energy in water using this suction strategy than it would with self-propulsion, Empa reported. A special propeller design also enables the robot to cross the air-water boundary in just 0.35 seconds.

Drone also masters slippery surfaces

In tests, for example, the robot rode along with a floating craft and recorded videos of hermit crabs, scallops and seaweed with an underwater camera. Likewise, the researchers had it fly out of the water and attach to an unstructured, rough rock. It also managed to attach to slippery, uneven surfaces in the water.

The researchers see such air-water robots as promising for environmental monitoring. For example, they could be used to inspect underwater structures, study marine life or detect icebergs.