A harsh environment, multi-plasma microsystem with pressure sensor, gas purifier, and chemical detector

A system for gas phase chemical detection in harsh environments has been developed that utilizes three microplasma-based devices: pressure sensor, gas purifier, and optical emission sensor. The devices all utilize microplasmas between thin-film electrodes and occupy a combined active area of 10.5 mm². They are fabricated on glass chips and enclosed in a 0.33 cm³ ceramic package. The optical emission sensor operates by fractionating and exciting gas species for chemical spectral detection. The pressure sensor measures the change in microplasma current distribution with pressure, and achieves a sensitivity of 9800 ppm/Torr at 200degC. The gas-purifying microscale sputter ion pump purifies the environment by selectively removing nitrogen and oxygen, and achieves a 56.5times reduction in nitrogen concentration relative to helium. This purification enhances the ability to detect trace amounts of gases. As a validation of this system, a spectral enhancement of 8times at 200degC for carbon line emission intensity relative to nitrogen has been demonstrated.