Researchers have developed a robot that is much akin to a seabird at least in its abilities if not design. The development of this robot will be a big leap in the industry of hybrid robotics. The robot has been aptly named RoboBee and is capable of both swimming and flying. Smaller than a paper clip, RoboBee has opened the gates to the development of an aqua aerial type of robotic vehicles.
The biggest challenge in designing such hybrid vehicles is the requirement for large wings to generate lift while flying. On the other hand, underwater vehicles need to minimise the surface area to reduce drag. The designers of RoboBee also face such a predicament.
The researchers at Harvard University, John A Paulson School of Engineering and Applied Science (SEAS) took a clue from puffins to solve this problem.
Puffins happen to be one of the most adept natural hybrid creatures in the world employing the same flapping motion to propel themselves through the air and water.
Kevin Chen, a graduate student at the Harvard Micro-robotics Lab at SEAS revealed that by various experiments and computational studies it was concluded that the flapping movement is very similar in aerial flight or while swimming.
The result of their collective effort is RoboBee – a micro-robot that is smaller than a paperclip, and it flies and hovers just like an insect. The RoboBee flaps its wings 120 times per second.
For making the transition to water, the team had to surmount the problem of surface tension. The tiny sized RoboBee could not break the surface tension of water. The design team found an ingenious method to overcome this hurdle.
The RoboBee flies over the water at an angle, ceases to flap its wings and drops like dead weight into the water to sink. The RoboBee then adjusts its flapping speed to adjust to the increased density of water. It now flapped its flapping speed to nine per second.
RoboBee: From Aerial to Aquatic
The RoboBee changed its direction by altering the stroke angle of its wings. The team used de-ionised water to prevent shorting and made the electrical connections waterproof by coating it with glue.
While this RoboBee can make the transition from air to water, it cannot make the changeover from water to air because its inability to generate enough lift without snapping one of its wings. It is the challenge for the next phase of the research, according to Chen.