a good example of a membrane, since it is composed of organic molecules that can easily form randomly, tends naturally to form a bubble because of the arrangement of the molecules -- hydrophillic at one end, hydrophobic at the other
A soap bubble is a very thin film of soap water that forms a sphere with an iridescent surface. Soap bubbles usually last for only a few moments and then burst either on their own or on contact with another object. They are often used as a children's plaything, but their usage in artistic performances shows that they can be fascinating for adults too.