Water striders have six legs and resemble large mosquitos. They can be spotted on the surface of calm or slow-moving water, eat living or dead insects and prefer to reside around ponds and marshes.
“The water’s surface needs to be pressed at the right speed for an adequate amount of time, up to a certain depth, in order to achieve jumping,” said Kyu Jin Cho, the study’s co-senior author, director of the Biorobotics Laboratory at Seoul National University.
Scientists found that the water strider employs a rotational leg movement to aid its takeoff from water. Researchers collected bugs to video their movements and study the complex mechanics that help them jump off of the water’s surface.“If you apply as much force as quickly as possible on water, the limbs will break through the surface and you won’t get anywhere,” said Robert Wood, a co-author on the study and founder of the Harvard Microrobotics Lab.
The scientists found that the best way to jump off of water is to maintain leg contact on the surface for as long as possible during jumping.
“Using its legs to push down on water, the natural water strider exerts the maximum amount of force just below the threshold that would break the water’s surface,” said Je-Sung Koh, another co-author of the study.
The robotic insect can exert up to 16 times its own body weight on the water’s surface without breaking through.
The team’s findings were published in the latest edition of the journal Science.