TED-Ed: How do geckos defy gravity? - Eleanor Nelsen

Geckos can climb vertical surfaces and walk upside down due to van der Waals forces, not claws or glue. These forces arise from temporary charge imbalances in molecules. Gecko toes have tiny structures called setae and spatulae that maximize these forces, allowing them to stick and release easily. This natural adhesion has inspired artificial materials, though not as strong as gecko toes, they enable humans to climb walls. The video explains the science behind gecko adhesion and its technological applications.

What principle do geckos use to stick to surfaces?

• Frictional force

• Chemical bonding

• Positive and negative charge attraction

• Magnetic attraction

What is the term for an atom's tendency to attract electrons?

• Electron affinity

• Atomic radius

• Electronegativity

• Ionization energy

How do van der Waals forces arise between molecules?

• Through permanent charges

• Due to temporary electron cloud shifts

• By forming covalent bonds

• Via magnetic fields

What are the tiny structures on gecko toes that help them stick to surfaces?

• Spatulae

• Microvilli

• Flagella

• Cilia

What is one application of gecko-inspired materials?

• Creating waterproof clothing

• Manufacturing solar panels

• Developing non-stick cookware

• Designing climbing gear