Researchers in Korea have developed a robotic insect which is able to jump on the surface of the water. The device was developed by scientists at Seoul National University, the Harvard John A Paulson School of Engineering and Applied Sciences and Harvard’s Wyss Institute for Biologically Inspired Engineering. The paper was published in the journal Science.
For the study the researchers investigated water striders, a species of semi-aquatic insects. These insects have legs which present slightly curved tips. The research team collected water striders and analyzed videos which showed their movements in order to understand the mechanism which the insects use in order to skim and jump off the surface of the water.
Co-senior author of the study Professor Ho-Young Kim from the Department of Mechanical and Aerospace Engineering at Seoul National University who is also the director of Micro Fluid Mechanics Lab at the same university and previously was Wyss Institute Visiting Scholar discovered that these insects use a rotational leg movement in order to take off from the surface of the water.
Kim worked together graduate researcher at the Micro Fluid Mechanics lab (Seoul National University) Eunjin Yang who is the first co-author of the study. They analyzed these insects in comparison with iterative prototypes of robotic insects. This helped the researchers realize that the best way to jump off the surface of the water is to keep the leg on the water surface for as long as possible during the jump movement.
When hey developed the robotic insect the scientists applies this mechanism. The device is provided with a “torque reversal catapult mechanism” which enables extreme locomotion without the need of intelligent control. The mechanism was inspired by the way flea jump. The catapult mechanism employs a burst of momentum and a limited thrust in order to launch the robotic insect off the water without disturbing the surface of the water. The catapult is activated by an automatic triggering mechanism. The robotic insect can use up to 16 times its body weight on the surface of the water without breaking through.
The study stated:
The resulting robotic insects can achieve the same momentum and height that could be generated during a rapid jump on firm ground – but instead can do so on water – by spreading out the jumping thrust over a longer amount of time and in sustaining prolonged contact with the water’s surface.”
Image Source: ibtimes.co.uk