Compact low-power gas detector for chemical alarms

Through an internally funded research program, Defiant Technologies has developed a compact chemical detector that can be tailored for a range of target analytes. The system uses a preconcentrator (PC) to collect and screen samples from the air, and a surface acoustic wave (SAW) microbalance to detect analytes when they are released from the PC. This PC-SAW system serves as a trigger for a secondary analysis channel that uses a micro-gas chromatographic (micro-GC) column to perform a more detailed analysis of the air. This combined approach provides high-confidence results while conserving power and minimizing response time. By properly selecting coatings on the PC, micro-GC and SAW, the unit can be designed for optimum performance in detecting specific target gases while ignoring interferents. This paper presents test results from our research and discusses some of the applications for this type of system.