The goal of this Engineering Microsystems: "XYZ" on a Chip project is to investigate the fabrication of a micro gas analyzer. A novel micro gas analysis system (MGA), incorporating a microplasma source for gas excitation, will be developed. Other components include a microspectrometer to measure the atomic and molecular emission intensity and an optical system coupling the light source and detector. The strategy is to scale down a Fabry-Perot spectrometer to approximately one millimeter in size. Several methods of increasing the spectral resolution of the microfabricated spectrometer will be implemented. These include feedback control of the position of the moveable mirror using capacitive sensing directly on the mirror's surface, post-fabrication of the reflective surfaces for improved optical quality, and design of microelectro-mechanical structures to optically collimate the plasma-generated light. The microplasma source will be fabricated using a single-mask process to form a 1 -mm diameter inductive coupling coil and two interdigitated capacitors for electrically resonating the coil. The integrated MGA will be tested using a representative metal contaminant (Hg) and exhaust contaminant (SO2) in air. This system will be experimentally characterized to determine the detection limits of each of these toxins.
The goal is to achieve a detection limit of at least 1 ppm. In conjunction with this goal, the fundamental and practical limits may be improved in future work. This project will produce a low-cost, low-power, portable gas analysis system capable of sensing a large number of airborne contaminants.
