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A balloon being placed first on a bed of nails and then a single nail.

Balloon Bed-of-Nails: Spreading the Force

Pushing against many points spreads the force and reduces pressure. In this demonstration a balloon pushed hard against a bed of nails doesn't pop, but when pushed gently against a single nail, the nail penetrates the skin of the balloon and it pops easily. On a superhydrophobic surface there are many hydrophobic features on the surface (the 'nails') and these are unable to penetrate the 'skin' of a water droplet caused by surface tension.