Water striders manage to do the seemingly impossible – walk on water – by using the surface tension of the water to move and, often, jump around. Although this movement comes naturally to the water strider, researchers have finally come to understand how they generate enough upward thrust to launch themselves out of the water.
To accomplish its water dance, the water strider turns the curved tips of its legs inward at a very low descending velocity, while applying a force that is just below what is required to break the water’s surface.
The research study’s co-author and Associate Professor in the Department of Mechanical and Aerospace Engineering and Director of the Biorobotics Laboratory at Seoul National University, Kyu Jin Cho, explained: “Water’s surface needs to be pressed at the right speed for an adequate amount of time, up to a certain depth, to achieve jumping.”
After a series of trial and error attempts to understand the mechanics of the water strider using robotic prototypes, a team of researchers from Seoul National and Harvard Universities have revealed a robotic insect that mimics the water strider’s movement. Their hypothesis was first published in the July 31 issue of Science.
Watch the video above to see both the water strider and its robotic counterpart in action.
Image and video credit: Seoul National University and Harvard University
Source: Wyss Institute