At scale robotic water strider
Jumping on water is a unique locomotion mode found in semi-aquatic arthropods, such as water striders. To reproduce this feat in a surface tension–dominant jumping robot, we elucidated the hydrodynamics involved and applied them to develop a bio-inspired impulsive mechanism that maximizes momentum transfer to water. We found that water striders rotate the curved tips of their legs inward at a relatively low descending velocity with a force just below that required to break the water surface (144 millinewtons/meter). We built a 68-milligram at-scale jumping robotic insect and verified that it jumps on water with maximum momentum transfer. The results suggest an understanding of the hydrodynamic phenomena used by semi-aquatic arthropods during water jumping and prescribe a method for reproducing these capabilities in artificial systems.
Related papers and patents
Je-Sung Koh, Sun-Pil Jung, Robert Wood and Kyu-Jin Cho, “A Jumping Robotic Insect Based on a Torque Reversal Catapult Mechanism”, Proceedings of the IEEE International Conference on Intelligent Robots and Systems (IROS), pp. 3796-3801, 2013. [PDF]
Je-Sung Koh and Kyu-Jin Cho, “Development of an Insect Size Micro Jumping Robot”, in Biomimetic and Biohybrid Systems (Living Machines 2014), Springer International Publishing, 2014, pp 405–407. [PDF]
Je-Sung Koh, Eunjin Yang, Gwang-Pil Jung, Sun-Pill Jung, Jae Hak Son, Sang-Im Lee, Piotr G. Jablonski, Robert J. Wood, Ho-Young Kim, and Kyu-Jin Cho, “Jumping on water: Surface tension–dominated jumping of water striders and robotic insects“, Vol. 349, no. 6247, pp. 517-521, Science, 2015. [PDF]