This Small Business Innovation Research Phase I research project will design and realize an on-chip detector that is capable of identification and measurement of environmental gas constituents. The device employs the recently introduced analytical science technology of Penning Ionization Electron Spectroscopy in plasma (PIES). PIES spectra contain distinct peaks that are specific for every component of the gas mixture. The performance of the on-chip PIES detector will be evaluated and PIES spectra for several environmental gases recorded using an upgraded test station consisting of a pre-concentrator device, gas chromatograph and control electronics. The project will advance the understanding of fundamental processes of chemi-ionization with participation of metastable helium atoms. It will also contribute to understanding basic processes occurring in microplasmas. The project will advance engineering of miniaturized analytical systems and help the designers by supplying information concerning behavior of a system as its dimensions change. The development a micro-sized gas analyzer will result in a cost effective and accurate tool for in situ environmental sensing that will improve control of the transport of polluted air masses to the residential and vacation areas. The proposed analyzer will also find applications in other areas, such as industrial process control, aerospace engineering, medicine, science and technology