Editorial for the Topical Issue: Recent Breakthroughs in Microplasma Science and Technology

Abstract

Microplasmas are plasmas where at least one dimension is in the submillimeter range. They can be thermal plasmas, where the gas temperature is far above the room temperature and is approaching the electron temperature, or they can be based on glow discharges and thus non-thermal in nature, with gas temperatures much below electron temperatures. The attraction of non-thermal microplasmas is that they can be operated stably at high gas pressures, in rare gases as well as in molecular gases and in gas mixtures, excited by direct current (dc) as well as by pulsed dc and alternate current (ac), radio frequency (rf), or microwaves. This allows one to exercise unprecedented control of the plasma operating parameters over a wide range and also makes these plasmas a versatile tool for many applications. Research into the basic properties of microplasmas gained prominence and recognition as a well-defined and stand-alone area within the larger field of plasma science and technology about 20 years ago. Since then, the activity in microplasma research and applications has continuously increased. A survey of peer reviewed papers on microplasmas published annually shows an order of magnitude increase in the number of papers published from 1995 to 2015 and this excludes papers that deal exclusively with technological applications where the microplasma is used solely as a tool. This Topical Issue aims to provide a snap shot of the current state of microplasma research and applications. This issue contains a comprehensive Topical Review entitled “20 years of microplasma research: a status