Miniature, Optical-Matrix System for Chemical, Biological, and Physical Measurements

There is a need to rapidly identify biological and chemical contaminants in regenerated air and water in extraterrestrial environments. Conventional sensors all fail this application because of deficiencies in several areas, including size, weight, versatility, power requirements, specificity, response time, and accuracy. Small. in situ, continuously operating, optical sensors can provide accurate, rapid, multiparameter detection. We propose to demonstrate the fundamental technology for a new type of in situ, multiparameter diagnostic sensor which uses optical microassembly to implement a spatial matrix. This is an innovative sensor system because of its ability to measure a variety of physical and chemical parameters by using one small matrix on a transparent substrate. A micro-optical array with input optical fibers directs several light sources to various cells of the matrix. Spectral changes to the input light. including absorption and fluorescence, are detected by a photodiode array. Selection of the transducer in each of the matrix regions will enable measurement of temperature, mass flow rates, pH, and chemical concentrations in gaseous or liquid media. Immunoassay techniques in some matrix cells provide extremely high degrees of selectivity and sensitivity for specific biological agents. Use of micro-optic assembly techniques will yield a small, rugged sensor design.