Propulsion Principles of Water Striders in Sculling Forward through Shadow Method
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Semi-aquatic arthropods skate on water surfaces with synergetic actions of their legs. The sculling forward locomotion of water striders was observed and analyzed in situ to understand and reproduce the abovementioned feature. The bright–edged elliptical shadows of the six legs of a water strider were recorded to derive the supporting force distributions on legs. The propulsion principles of water striders were quantitatively disclosed. A typical sculling forward process was accomplished within approximately 0.15 s. Water striders lifted their heads slightly and supported their weight mainly by the two driving legs to increase the propulsion force and reduce the water resistance during the process. The normalized thrust–area ratio (defined as the ratio of the propulsion force to the projected area) was usually lower than 0.4 after sculling for approximately 0.08 s. The entire normal supporting force remained nearly constant during a stroke to reduce the mass center fluctuation in the normal direction. In addition, water striders could easily control the locomotion direction and speed through the light swinging of the two hind legs as rudders. These sculling principles might inspire sophisticated biomimetic water-walking robots with high propulsion efficiency in the future.
Keywordsshadow method water strider sculling forward locomotion propulsion principle
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This work is supported by the National Natural Science Foundation of China (Grant No. 51425502).
- Bowdan E. Walking and rowing in water strider, gerris- remigis. I. Cinematographic analysis of walking. Journal of Comparative Physiology, 1978, 123, 43–49.Google Scholar
- Denny M W. Air and Water: The Biology and Physics of Life’s Media, Princeton University Press, Princeton, New Jersey, USA, 1993.Google Scholar
- Suter R B,Wildman H. Locomotion on the water surface: Hydrodynamic constraints on rowing velocity require a gait change. Journal of Experimental Biology, 1999, 202, 2771–2785.Google Scholar
- Song Y S, Suhr S H, Sitti M. Modeling of the supporting legs for designing biomimetic water strider robots. IEEE International Conference on Robotics and Automation, Orlando, FL, USA, 2006.Google Scholar
- Suhr S H, Song Y S, Lee S J, Sitti M. Biologically inspired miniature water strider robot. Robotics: Science and Systems, 2005, 1, 319–325.Google Scholar
- Suter R B, Rosenberg O, Loeb S, Wildman H, Long J H. Locomotion on the water surface: Propulsive mechanisms of the fisher spider dolomedes triton. Journal of Experimental Biology, 1997, 200, 2523–2538.Google Scholar
- Wilson R M. Archimedes’s principle gets updated. Physics Today, 2012, 65, 15–17.Google Scholar
- Leenaars A F M, Obrien S B G. Particle removal from silicon substrates using surface-tension forces. Philips Journal of Research, 1989, 44, 183–209.Google Scholar