A microplasma generator is made of elongated semiconductor structures in a spatially defined cavity. A microplasma is generated whenever a voltage is applied across the elongated semiconductor structure. A gate electrode lies adjacent to the semiconductor, outside the microplasma cavity, separated by an insulating material. This gate electrode is configured such that a saturation current is altered when the voltage is applied. A series of generators may be arranged in a way that applying a voltage along the longitudinal axis will generate microplasma within the spatially defined cavities.