Forget Olympics high jumpers; if you really want to see some impressive vertical leaping look no further than aquatic animals such as the whale, dolphin, and even the humble mobula rays — all of which are capable of launching themselves out of the water and into the air with graceful ease. Borrowing from this technique, researchers from Cornell University have developed a breaching robot that is able to pull off similarly dazzling feats in a tank of water.
“In this study, we [elucidated] the physics of jumping aquatic animals by analyzing biological data, conducting simplified experiments, and theoretical modeling,” Sunghwan Jung, associate professor in Cornell’s Department of Biological and Environmental Engineering, told Digital Trends.
“By firing axisymmetric bodies out of water, we found two distinct regimes that govern jump height as related to the ratio of inertia to gravity,” Jung continued. “Based on these findings, a bio-inspired robot was built to jump out of water. When exiting water, the robot carries a large volume of fluid referred to as an entrained mass. A theoretical model [was] developed to predict the jumping height of various water-exiting bodies, which shows that the mass of the entrained fluid relative to the mass of the body limits the maximum jumping height.”
The researchers chose to borrow the techniques exhibited by two of the animals they studied. These included copepods, a group of small crustaceans found in virtually every water environment, and frogs. Both use the flapping motion of appendages to leap. For copepod, this is done by flicking their antennae downward to jump. For frogs, this is achieved by pushing down and then flapping their feet.
The team’s robot — which resembles a door hinge attached to a rubber band — incorporates a similar flapping motion using its two appendages. As can be seen from the above video, the results are fairly impressive. However, Jung noted that there is still much more work to be done before this development can be incorporated into real-world robotic systems.
“I would like to emphasize that our robot shows a proof-of-concept and is far from real-world deployments yet,” he said. “But we are thinking of using this robotic system to surveil near water basins to monitor the environments. For example, we [could one day] deploy this robot in a river. It will flow down along the river without any propulsive mechanism. When the robot senses a toxic chemical around, it jumps and takes a picture of the location or send out an external signal to report the toxicity in the river.”
