A robot smaller than a paperclip is causing big buzz after engineers were able to make it swim as well as fly.
RoboBee, a tiny robot build at the Harvard John A. Paulson School of Engineering and Applied Science (SEAS), has been able to fly for some time. Recently, Discovery News reports, it was given a modified flapping technique to allow it to swim underwater as well.
Most robots that fly use designs quite different from the designs used on swimming robots. Engineers looked at birds that can both fly and swim, such as the puffin, to figure out how to make a robot that can do both. Studies were conducted to determine that the biggest difference between a puffin flying and swimming is the wing speed according to graduate student Kevin Chen.
Through various theoretical, computational and experimental studies, we found that the mechanics of flapping propulsion are actually very similar in air and in water. In both cases, the wing is moving back and forth. The only difference is the speed at which the wing flaps.
There were other challenges due to the minuscule nature of the RoboBee. Because it is so light, it has a tough time breaking the surface tension of water. It sits on the water’s surface without moving its wings and waits for gravity to pull in underwater before flapping again.
The wings themselves are very thin and fragile. In the air they beat 120 times per second. They need to slow down considerably when swimming so they don’t snap. In the water the wings beat 9 times per second reports CNET.
Power for the RoboBee is supplied from an external power supply via wire so it is tethered at all times. It also is unable to fly out of the water at this time as it can’t get enough lift in the water without damaging its wings.
Chen expressed his excitement that this advance in robotics will help develop better robots, not just insect sized but also larger robots as well.
What is really exciting about this research is that our analysis of flapping-wing locomotion is not limited to insect-scaled vehicles. From millimetre-scaled insects to metre-scaled fishes and birds, flapping locomotion spans a range of sizes. This strategy has the potential to be adapted to larger aerial-aquatic robotic designs.
Another underwater robot made news recently when the project founded by NASA engineer Eric Stackpole raised over $650,000 toward an underwater drone called Trident.