A Five-Microvalve Fully Integrated Preconcentrator

A five-microvalve fully integrated preconcentrator (PC) is presented that has been developed to rapidly preconcentrate gas before injecting the sample into a flame ionization detector (FID). A one-muL PC chamber uses two microvalves to load the sample gas, and three microvales to route the sweep gas through the PC to the FID. Each microvalve has a switching time less than 50 mus. The speed of this microvalve is enabled by an innovative electrode design. The 5 fast microvalves enable an independently controllable timing sequence for collecting a sample in a PC, sealed rapid heating, and injecting the now concentrated sample in a short pulse directly into the FID, the signal of which is proportional to the concentration in the band. The five-microvalve device allows a MEMS gas analyzer or gas chromatograph (GC) to sniff chemical agents, toxic industrial compounds, and other volatile compounds in seconds.