Soap bubbles are applied nanotechnology for DIY and amazement.  Many principles that modern nanotechnology uses technically are at work in soap bubbles. Professor Norio Taniguchi established the following definition as early as 1974: "Nanotechnology is mainly about the separation, stabilisation and deformation of materials by an atom or a molecule".

In soap bubbles, the two main ingredients water and so-called surfactants produce exactly these effects: Forces between the nanoscopic surfactant molecules lead to the formation of an ordered molecular layer on the water surface. When this layer is pulled out, a wafer-thin double layer is formed. The two surfactant layers trap a thin film of water.  The forces between the water molecules are strong enough to hold this skin together. If you blow air into this elastic skin, a bubble forms. Small bubbles are spherical. With large bubbles, the air movement causes irregular shapes.
The double reflection on the double layer with a thickness of a few tens to a few thousands of nanometres is responsible for the colourful iridescence. The thickness of the layer can be seen from the colours. More information can be found here: LEIFIphysik: Soap Bubble Optics

Secret recipes

Secret recipes
Mixes to make yourself:

  • 1000 ml (5 cups) water
  • 45 ml (3 tablespoons) washing-up liquid
  • 2 g (1/2 teaspoon) guar gum optional
  • 15g (1 tablespoon) glycerine.


Dissolve guar gum in 200 ml (1 cup) warm water, stir well and leave overnight. Dissolve the washing-up liquid in the remaining 800 ml (4 cups) of water. Add half of the guar gum mixture.   Let the solution sit for another hour or so and then it's time for the first test! If you are not yet satisfied with the result, you can add more guar gum in small steps. The optimal mixture depends on the humidity, temperature and wind conditions. If the air is dry, a little glycerine can also prolong the life of the bubbles.
According to our tests, the best surfactant mixture for soap bubbles is the Ultra-Fee brand (tell us if you find a better detergent!).

And a very secret tip: add 2g (1/2 teaspoon) of baking soda to the solution at the end. This lowers the pH and makes the bubbles more stable.

"Pimping" purchased solutions: Add some dissolved guar gum here too. This gives larger and longer-lasting bubbles.