How does it work?
A singlet is formed between the tip and the highly curved surface of the skin. A voltage is applied to the electrode, the skin protrudes as a floating electrode, and at a certain moment the voltage becomes sufficient for a partial ionization of air to occur in a narrow corridor between the needle tip and the skin. Thus, the procedure is contactless!
The charged particles begin to move at a tremendous speed to the surface of the skin and forcefully hit it, while a very rapid release of a large amount of energy in a small volume occurs. As a result of instant evaporation of everything that is in this volume (water, organic compounds), a neat depression is formed, the walls of which look dark due to carbonization.
It is important that the heating of the adjacent undamaged areas does not occur either to the side or inward - the process of evaporation and the formation of a charred wall proceeds so quickly. Not only liquid, but also liquid structures evaporate, therefore, from the point of view of physics, this process is correctly called sublimation, that is, the transition of a substance from a solid state to a gas, bypassing the liquid phase.