Researchers of Harvard University’s John A. Paulson School of Engineering and Applied Science (SEAS) have designed an insect-sized robot that can fly as well as swim. Now, the first obvious question would be, how were they able to minimize surface area issue?
Aerial vehicles require large airfoils like wings or sails to generate lift and thereby, increasing the surface area. But, to swim, the lesser the surface area the lesser the drag. They had to overcome this important issue before they could design the insect-sized robot. Researchers at SEAS observed Puffins, a rare bird that uses its wings to fly and swim underwater, to create RoboBee, the first ever robot that can fly as well as swim under water.
“Through various theoretical, computational and experimental studies, we found that the mechanics of flapping propulsion are actually very similar in air and in water,”- said Kevin Chen, a graduate student at the Harvard Microrobotics Lab at SEAS.
The size of the robot is another technological marvel. The RoboBee is smaller than a paperclip; flies and hovers like an insect. The insect-sized robot has powerful wings that can flap at the rate of 120 times per second.
To make the transition from air to water, the RoboBee had to break the surface tension of the water, which is 1,000 times higher than that of air. To overcome this hurdle, the RoboBee hovers over water at a particular angle, instantly switches off its wings, and crashes into the water in order to sink. To prevent the robot from short circuiting, the water used was deionised and the electrical connections were coated with glue.
Though, the transition from air to water was quite a success, the insect-sized robot still cannot fly from water to air. This is mainly because RoboBee couldn’t generate enough lift. Solving this would make the first ever robot that can fly as well as swim under water perfect.