How Do Geckos Stick to Walls?

Each gecko toe is covered in ridges called lamellae, which carry hundreds of thousands of tiny hairs known as setae. Each seta splits at its tip into hundreds of even smaller branches called spatulae, only about 200 nanometres wide. These tips get so close to a surface that weak van der Waals forces between molecules add up to a powerful grip. The adhesion is dry, so geckos need no glue or suction, and they release their grip by peeling the toe up at an angle. Scientists have studied the system to make reusable adhesives and climbing grippers for robots.