Drone dives like a seabird, bursts skyward like a flying fish

We have seen a few aerial drones capable of venturing underwater, but none that can enter and exit the marine environment quite like the so-called AquaMav. Built by engineers at Imperial College London, the drone uses collapsible wings to dive like a fish-hunting seabird and scoop up water samples from beneath the surface, and then launch like a flying fish when it's time to return to the skies.

Models like the Loon Copter, the HexH2o and CRACUNS have explored the possibilities of amphibious aircraft, but in the view of the Imperial College researchers, drones that can transition from the air to the water tend to make some sort of compromise. So the team sought to overcome this by designing a thin missile-shaped drone that can use a reconfigurable wing for smoother entry.

The drone weighs only 200 g (7 oz) and flies through the air courtesy of a fixed-wing design. But when it's time to get wet, the wings fold up in line with its slender body and allow it to burst through the surface of the water, in much the same way a gannet dives for fish – something it does at up to 97 km/h (60 mph).

After collecting a water sample, the drone then uses an internal carbon dioxide tank and hollow tube to generate a powerful burst of water. This is enough thrust to launch it out of the water and into the air with the speed needed to begin gliding once again. Like its entry, the exit is also inspired by nature, this time, by the incredible ability of flying fish to leap into the air and escape prey.

Once in the air, the AquaMav can zip along at 30 mp (48 km/h) and its battery allows for 14 minutes of flight time. The researchers say this allows the drone a range of around 5 km (3.1 mi), something that could allow operators to remain a safe distance away when dealing with hazardous situations.

"During an emergency scenario such as a major oil leak, an AquaMav could fly and dive into isolated patch of water, where it could collect samples or loiter and record environmental data," Mirko Kovac, the director of the Aerial Robotics Lab in Imperial's Department of Aeronautics. "The vehicle could then perform a short take-off and return to its launch site to submit samples for analysis. This would enable a fast, targeted response that could not be matched by the current methods."

Beyond dire applications, AquaMav could also be used for more benign things like gauging water salinity as a way of monitoring climate change, or checking water quality in reservoirs. Currently in prototype form, the researchers are next looking to team up with oceanographers to further explore the AquaMav's potential and see how it holds up in different weather and water conditions.

The research is published in the journal Interface Focus.

Source: Imperial College London