Refers to improving the wetting of liquids on a surface by means of upstream plasma cleaning. This cleaning is used to reduce oxides on metal surfaces and remove impurities. Argon hydrogen can be cited as an example. The argon molecules are put into a higher energy state by a microwave and brought into contact with the surface to be cleaned through a controlled gas flow. In the process, argon removes the first atomic layers from the surface. The excited hydrogen reduces the now exposed oxides and the bare metal surface remains.