UNIVERSAL CHEMICAL VAPOR SENSORS WITH COMBINED MASS AND SPECTROSCOPIC SELECTIVITY

THE OBJECTIVE OF THIS PHASE I PROJECT IS TO DEMONSTRATE THE TECHNICAL FEASIBILITY OF COMBINING MASS-SENSITIVE AND OPTICAL SPECTROSCOPIC TECHNIQUES TO PROVIDE A UNIVERSAL SENSOR FOR BOTH IDENTIFICATION AND QUANTIFICATION OF VAPOR PHASE CONSTITUENTS WITH SENSITIVITY BETTER THAN 1 PART PER MILLION. THE RESEARCH IS DESIGNED TO SIMULTANEOUSLY DETECT THE MASS CHANGE AND THE VIBRATIONAL SPECTRUM OF THE SPECIES CAUSING THAT CHANGE. NOVEL SURFACE MODIFICATIONS OF THE MASS-SENSITIVE COMPONENT BEING STUDIED THAT GIVE RISE TO SOME SELECTIVITY FOR VAPOR PHASE SPECIES AND AN ENHANCEMENT OF THE VIBRATIONAL SPECTROSCOPIC SIGNAL. PHASE I ENTAILS DEMONSTRATION OF THE TECHNIQUE FOR SULFUR DIOXIDE, NITROGEN DIOXIDE, BENZENE, AND TOLUENE, BOTH ALONE AND FOR QUANTITATIVE AND QUALITATIVE RESOLUTION OF BINARY MIXTURES IN AIR. A GOAL OF PHASE I IS TO DEMONSTRATE SENSITIVITY TO <100 PPM IN AIR AND TO ESTABLISH THE SENSOR'S REVERSIBILITY AND RESPONSE SPEED. IT IS ANTICIPATED THAT THE SMALL SENSORHEAD CAN BE COUPLED BY FIBER OPTICS TO COMPACT OPTICAL AND CONTROL INSTRUMENTATION FOR PROBING ADVERSE AND/OR REMOTE ENVIRONMENTS.