Natures wonders: water striders say afloat (Introduction)

by David Turell , Monday, July 20, 2015, 17:27 (3412 days ago) @ David Turell

The hairs on their legs collect droplets through their shape and the drops fall off:-http://phys.org/news/2015-07-legs-striders-repel.html-"Water striders are bugs with the ability to run on water, bioengineered by nature to distribute their weight to long outer legs so that they are supported by water surface tension. They thrive in climates of high humidity, thus confronting an environment of both liquid water and vapor, and evolved superhydrophobic legs in order to remove the risk of saturation affecting their weight dynamics.-" A water strider's leg is a one-centimeter cylinder covered by an array of inclined, tapered hairs of conical shape, which the researchers imaged using X-ray computed tomography and scanning electron microscopy. The surfaces of the individual hairs have longitudinal and quasi-helicoidal nanogroves, which the researchers note increase their hydrophobicity by enhancing the mobility of drops. "Without any external force, tiny condensed droplets get removed from striders' legs, owing to the presence of oriented conical setae," the authors write. When exposed to mist, micrometric drops of water condense at the surface of the hairs, moving away from the tip and sinking down into the texture."