Twenty years of Hakone symposia: From basic plasma chemistry to billion dollar markets

The progress of atmospheric-pressure non-thermal plasma technology since the first Hakone symposium in 1987, later referred to as Hakone I, is summarized. Advances in the fundamental understanding of the discharge physics of corona discharges and of dielectric barrier discharges led to a number of technical developments that resulted in improved industrial processes and novel products including excimer-based ultraviolet sources and fluorescent lamps, and flat large-area plasma display panels using Xe vacuum ultraviolet radiation. The newly established markets surpass the original market of ozone generators by two orders of magnitude. Recent research activities devoted to microcavity plasma devices address an entirely new realm of discharge physics with fascinating new applications.