What Is This?
Photo: © PAUL D. STEWART
THESE COLORFUL, five-pointed objects are the feet of several geckos, small lizards found in the Tropics and some parts of the United States.
Geckos spend much of their time hanging from walls and ceilings, and can even scamper across polished glass upside down. How they manage such gravity-defying feats puzzled scientists until recently. But new research shows millions of tiny hairs on the bottom of geckos' feet are the key. Each of these hairs ends in hundreds of tips so small that they can stick to individual molecules in walls or other surfaces through an attraction called van der Waals force, scientists have found. The force is so strong that a 280-pound gecko could hang out comfortably from a ceiling using nothing but its hairy feet.
What works for geckos may work for people. Biologist Kellar Autumn of Lewis and Clark College notes, "This opens the door to manufacturing dry, self-cleaning adhesives that work under water and in a vacuum." Would that be a big stick-it item?