Ionized plasmas like those in neon signs and plasma TVs can sterilize water and make it antimicrobial as well, according to researchers studying the potential to use inexpensive plasma-generating devices to create sterile water in developing countries, disasters areas, and battlefields.

Plasmas are the fourth state of matter after solid, liquid, and gas. They are formed when gases are energized, stripping atoms of their electrons to create a collection of free moving electrons and ions.