Fine bubbles are classified into two types according to the size of the bubbles: micro-sized microbubbles (MB) and nano-sized ultrafine bubbles (UFB) (previously called 'nanobubbles'). Ultrafine-Bubble (UFB) (previously called 'nanobubbles'), which are nano-sized.

These are not only smaller bubbles, but also have various characteristics that differentiate them from the bubbles of a few millimetres (mill bubbles) that we normally see.

Size of UFB

Too small to see.
500-1000 in a row across the width of a hair

1. The bubbles are too small and have very little buoyancy.
2. Negatively charged, so the bubbles don't stick together.
3. Cationic shells.
   These three features ensure that the bubbles do not disappear and remain for a long time. UFB remains even when hosing or spraying.

UFB is negatively charged and therefore attracts cations (+)

Collision to dirt and crushing with 30 Bar

The surrounding water pressure, intermolecular forces and electrostatic forces create an atmospheric pressure of 30 bar inside the bubble - for viruses and bacteria of the same size as UFB, the force of a 30-bar bubble bursting is incredibly destructive. The impact strips off the dirt.