Robotic Insect Built By Scientists Can Stride On Water
Walking on water might be something only a human with superpowers can do, but it is actually a quite natural phenomenon in some species. Many small living creatures use water’s surface tension to maneuver themselves around.
And one of the most intricate maneuvers, jumping on water, is second nature to a species of semi-aquatic insects called water striders that not only skim along water’s surface but also generate enough upward thrust with their legs to launch themselves airborne from it.
Now an international team of scientists has announced a novel robotic insect that can jump off of water’s surface. In developing the device, they have uncovered new insights into the natural mechanics that allow water striders to jump from rigid ground or fluid water with the same amount of power and height.
Water’s surface, according to one of the study’s senior authors, Kyu Jin Cho, needs to be touched at the right velocity, for an adequate amount of time, up to a certain depth, in order to achieve jumping. A water strider is capable of doing all these things flawlessly.
Trial and Error
It took the team several trial and error iterations to completely grasp the mechanics of the water strider, using robotic prototypes to test and shape their hypotheses.
The robotic insect was built using a “torque reversal catapult mechanism” inspired by the way a flea jumps, which allows this kind of extreme locomotion without intelligent control.
For the robotic insect to leap off water, the lightweight catapult mechanism uses a burst of momentum coupled with limited thrust to propel the robot off the water without breaking the water’s surface. An automatic triggering mechanism, built from composite materials and actuators, was employed to activate the catapult.
Tiny robots like these could someday be used for search operations, among other applications. Because this design was fabricated by manufacturing folded composite structures which self-assemble, it would be economical to produce in large batches.