Sino-UK scientists design air-water robot drone inspired by adhesive fish

A team of Chinese scientists, along with their international counterparts, have designed a robotic drone capable of crossing the air-water boundary and hitching themselves to moving objects.

The scientists from Beihang University and Imperial College London drew inspiration from remora fish, a family of species known for their adhesive discs that help them catch a ride on marine creatures like whales and sharks. The unique ability of this fish to hitchhike helps it to conserve energy.

The 3D-printed, untethered robot can switch from an underwater drone to an aerial vehicle in less than 1 second due to the unique design of its propellers, which make the transition between water and air usage faster than most previous aerial-aquatic robots, according to the study published Thursday in the journal Science Robotics.

The robot is installed with a remote-controlled suction pad that can stick to wet and dry surfaces with different textures, even onto moving objects, according to the study.

It can rapidly attach to and detach from challenging surfaces both in the air and underwater, including curved, rough, unfinished, and biofouling surfaces, and achieve long-duration adhesion with minimal oscillation.

Untethered drones are good at working in expansive or remote environments, but one obstacle to their application is that their batteries tend to drain quickly. The hitchhiking mode helps solve the energy problem.

During application tests, the robot hitched a ride on a swimming host vehicle to obtain seabed images of hermit crabs, scallops, and seaweed. It consumed significantly less energy, spending roughly 19 times less power than it would have by using self-propulsion, according to the study.

Also, the robot's passively morphing propellers that unfold in the air and fold underwater can cross the air-water boundary in 0.35 of a second.

In the future, the robot's design could enable autonomous biological detection, monitoring and tracking capabilities in a wide variety of aerial-aquatic environments, says the paper's corresponding author, Wen Li of Beihang University.

Xinhua