How do geckos defy gravity to climb walls?

💡 The Answer

• Geckos use millions of tiny hair-like structures called setae on their toe pads to create adhesion.
• Each seta branches into hundreds of nanometer-sized spatulae, increasing surface contact area.
• The attraction is due to van der Waals forces, weak intermolecular forces that become significant with large surface area.
• This mechanism allows geckos to cling to smooth surfaces and even support their entire body weight.