Microplasmas, an emerging field of low-temperature plasma science and technology

Spatially confining atmospheric pressure, non-equilibrium plasmas to dimensions of 1 mm or less is a promising approach to the generation and maintenance of stable glow discharges at atmospheric pressure. Such microdischarges or microplasmas represent systems with new and fascinating challenges for plasma science such as the possible breakdown of "pd scaling" and the increasing dominance of boundary-dominated phenomena. Pulsed excitation on a sub-microsecond time scale results in microplasmas with significant shifts in both the temperatures and energy distribution functions of ions and electrons. This allows for the selective production of chemically reactive species and opens the door to a wide range of new applications of microplasmas in areas such as environmental remediation, biology and biomedicine, intense light sources in the ultraviolet and vacuum ultraviolet, and gas and surface analysis -- to name just a few. This topical review addresses some of the scientific challenges and technological opportunities afforded by microplasmas.