ITHACA, N.Y., Feb. 2 (UPI) -- Cornell University scientists say they've created a device that uses water surface tension as an adhesive that might allow humans to walk on walls.
The researchers, led by Professor Paul Steen and post doctoral scientist Michael Vogel, said the device is the result of inspiration drawn from a beetle native to Florida, which can adhere to a leaf with a force 100 times its own weight, yet also instantly "unstick" itself.
The device consists of a flat plate patterned with holes, each microns in size. A bottom plate holds a liquid reservoir, and in the middle is another porous layer. An electric field applied by a 9-volt battery pumps water through the device and causes droplets to squeeze through the top layer. The researchers said the surface tension of the exposed droplets makes the device grip another surface -- much the way two wet glass slides stick together.
"In our everyday experience, these forces are relatively weak," Steen said. "But if you make a lot of them and can control them, like the beetle does, you can get strong adhesion forces."
The study that was funded by the Defense Advanced Research Projects Agency and the National Science Foundation appears in the early online edition of the Proceedings of the National Academy of Sciences.