How do geckos adhere to surfaces?

Scientists have put to rest the age-old question of how geckos stick to walls. The answer is van der Waals forces, molecular attractions that operate over very small distances. The researchers are already trying to use their discovery to make wall-climbing robots and design materials that stick to dry surfaces. read more

Geckos can stick to surfaces because their bulbous toes are covered in hundreds of tiny microscopic hairs called setae. Each seta splits off into hundreds of even smaller bristles called spatulae. Scientists already knew that the tufts of tiny hairs get so close to the contours in walls and ceilings that the van der Waals force kicks in. read more

“Two millennia later, we have solved the puzzle of how geckos use millions of tiny foot hairs to adhere to even molecularly smooth surfaces such as polished glass,” says Kellar Autumn, lead author of an article in this week’s Proceedings of the National Academy of Sciences. read more

If the toes are hydrophilic and the surface is hydrophilic, the water-love of both surfaces could be enough to stick them together – think of how two pieces of paper, not at all sticky, can be stuck to each other by glue, since each one sticks to the glue. read more