Makers of robotic pollinators, "RoboBees," have revealed yet another breakthrough in their invention: the miniature bee robots can swim and turn into submarines.

The additional features of the robots were presented by its creators on Sept. 29, 2015 at the 2015 Institute of Electrical and Electronics Engineers (IEEE)/RSJ International Conference on Intelligent Robots and Systems. The researchers explained how they were able to make their robots swim, which is an ability that even real bees are not able to naturally exhibit. The RoboBees were said to have the ability to fly in the air, crash onto the water and transform into a tiny submarine.

In 2013, researchers from Harvard University headed by Robert Wood, an engineering professor, introduced the RoboBees, which can lift off the ground and flutter in midair when fasten to a power source.

RoboBees were engineered by its makers in the aim of addressing the unprecedented lack of bee populations.

The ability of insects like bees to employ sophisticated flying and landing techniques are made possible through its small nervous system and wings. Experts were then starting to understand how these creatures execute these actions from sensorimotor transduction to the unstable aerodynamics of its wing movement. With the motivation to create a robotic structure to mimic these abilities, the researchers came up with the RoboBees and published a paper in the journal Sciencemag on May 2013.

Now, the same researchers presented a new paper, demonstrating not just the aerial abilities of the robots, but its aquatic prowess as well. Using a computational fluid dynamics (CFD) simulation, the researchers were able to showcase the interaction between fluids and wings both in the air and in water. With additional aid from system dynamics analysis, the researchers then predicted that a multi-modal approach to flapping wings will enable the robots to move in both air and water. "We demonstrate for the first time a flying and swimming capable flapping-wing insect-like robot," the researchers wrote.

In this work, the key discovery made by the experts was that swimming is actually similar to flying. Both actions require one to propel through fluid by flapping a wing (or in fish, a fin), back and forth. The speed required for creatures to fly is higher compared to swimming, which is relatively relaxed.

The only disadvantage that RoboBees may have in doing its swimming feat is its tiny size. The surface tension of the water is just enough to prevent the small robots from sinking. The said problem may be hard to solve for fully loaded RoboBees that are equipped with batteries.

Crashing from the air to the water seems easier than the flying to swimming. In the future, the researchers would tackle this and work on the RoboBees' transition from water to air.

Photo: IEEE Spectrum | YouTube