* a [professor at Georgia Tech](https://www.me.gatech.edu/faculty/hu) that studies poop, pee, and eyelashes, among other things. * Assistant Professor of Mechanical Engineering; he holds a joint appointment in the Department of Biology. * focused on fluid dynamics, solid mechanics, biomechanics, locomotion, and physical applied mathematics * However, little is known about how optimal propulsion is obtained with when both surfaces are flexible or compliant. This is an important area because flexible surfaces provide means to modulate friction in ways rigid surfaces cannot. We have begun to explore this area by a combined experimental and theoretical investigation of ==snake propulsion==. * Water striders are insects that support their weight by surface tension and propel themselves by sculling with their hydrophobic legs. Previous investigators assumed that the hydrodynamic propulsion of the water strider relies on momentum transfer by surface waves. Our flow-visualization experiments reveal that the strider transfers momentum to the underlying fluid not primarily through capillary waves, but rather through hemispherical vortices shed by its driving legs. - D. Hu, B. Chan, J. W. M. Bush. 2003. The Hydrodynamics of Water Strider Locomotion. _Nature_ **424**, 663-666. - D. Hu and J. W. M. Bush. 2005. Meniscus-Climbing Insects. _Nature_ **437**, 733-736. - J. W. M. Bush and D. Hu. 2006. Walking On Water: Biolocomotion at the Interface. _Annual Review of Fluid Mechanics_ **38**, 339-369. - D. Hu, B. Chan, and J. W. M. Bush. 2007. Water-Walking Devices. _Experimental Fluids_ **43**, 769-778. - J. W. M. Bush, D. Hu, and M. Prakash. 2008. The Integument of Water-Walking Arthropods: Form and Function. _Advanced Insect Physiology_ **34**.