A team of Harvard scientists has invented a robot that can dive from the air into the water and continue swimming – check it out here.
Scientists have just created something that was previously only thought capable by alien spacecraft. According to a report from Phys.org, a team of Harvard engineers have once again turned to nature for their inspiration as they created the first robotic bee that can both fly in the air and swim underwater.
A Russian engineer first proposed the idea in 1939, but nobody thought something like that would be possible. Despite their best efforts, scientists have failed at making an air-to-sea vehicle for decades.
The team of engineers, from the Harvard John A. Paulson School of Engineering and Applied Science (SEAS), drew inspiration from the puffin as they designed the world’s first flying submarine. Puffins are one of the few highly specialized birds that can dive-bomb from the air and continue gliding through the water.
To make the machine work, the researchers needed to have large airfoils or wings to create lift while flying, as well as minimal surface area to minimize drag underwater. According to Kevin Chen, a graduate student at the Harvard Microbiotics Lab, the team performed a number of theoretical, computational, and experimental studies to determine that the physics behind flying through air and water were actually quite similar. In both environments, wings move up and down to propel the body forward. The biggest difference, Chen said, was the speed at which they flapped their wings.
The engineering team at SEAS got to work creating something that would stand up to the test of flying in both the air and the water. They came up with a tiny insect-like robot, called the RoboBee, as their first iteration of a flying submarine vehicle. They presented their research and invention at the International Conference on Intelligent Robots and Systems in Germany. Chen, the study’s lead author, won the award for best student paper.
Chen was helped by fellow graduate student Farrell Helbling, postdoctoral fellows Kevin Ma, and Nick Gravish, and Robert J. Wood, a core faculty member at the Wyss Institute for Biologically Inspired Engineering and the Charles River Professor of Engineering and Applied Sciences at SEAS.
The RoboBee, which was designed in Wood’s lab, is only the size of a paperclip. It can fly and hover like a dragonfly, and beats its wings up to 120 times per second.
The biggest problem with getting a flying robot into the water was figuring out how to break the surface tension. Because the robot was so tiny, it needs help exerting enough force on the surface of the water to actually break through.
The RoboBee has an interesting fix. It hovers above the water at an angle, and stops flapping its wings. As it accelerates towards the water, it generates enough force to break the surface tension and plunge below.
The next problem was finding out a way to make the RoboBee tough enough to deal with the 1000x density it would experience once inside the water. Its wings would need to be adjusted so that they didn’t snap off trying to flap at 120 beats per second.
The robot decreases its flapping speed from 120 beats per second to just nine once it enters the water, but there were no other changes to the original design. It can steer by adjusting the angle at which its wings beat, much like it does in the air. The team prevented the robot from shorting out in the water by sealing its electronics with glue and using deionized water for their demonstration.
The struggle to create a true flying submarine is far from over, however. The RoboBee can dive from the air into water, but it still cannot return to the air from the depths. Chen hopes that he can continue researching new ways to make it possible for the robot to transition between the two environments in both directions.
Perhaps the team could look towards the flying fish, which effortlessly breaches the water’s surface from below and glides above to evade predators. Nature has already drawn the designs, but it’s up to engineers to put them to good use.
