A prototype portable instrument employing micro-preconcentrator and FBAR sensor for the detection of chemical warfare agents

The presence of chemical warfare agents (CWAs) in the environment is a serious threat to human safety, but there are many problems with the currently available detection methods for CWAs. For example, gas chromatography-mass spectrometry cannot be used for in-field detection owing to the rather large size of the equipment required, while commercial sensors have the disadvantages of low sensitivity and poor selectivity. Here, we develop a portable gas sensing instrument for CWA detection that consists of a MEMS-fabricated micro-preconcentrator (mu PC) and a film bulk acoustic resonator (FBAR) gas sensor. The mu PC is coated with a nanoporous metal-organic framework material to enrich the target, while the FBAR provides rapid detection without the need for extra carrier gas. Dimethyl methylphosphonate (DMMP), a simulant of the chemical warfare agent sarin, is used to test the performance of the instrument. Experimental results show that the mu PC provides effective sample pretreatment, while the FBAR gas sensor has good sensitivity to DMMP vapor. The combination of mu PC and FBAR in one instrument gives full play to their respective advantages, reducing the limit of detection of the analyte. Moreover, both the mu PC and the FBAR are fabricated using a CMOS-compatible approach, and the prototype instrument is compact in size with high portability and thus has potential for application to in-field detection of CWAs. (C) 2022 Author(s).

Automated summary

This study develops a portable gas sensing instrument for the detection of chemical warfare agents (CWAs). The instrument consists of a micro-preconcentrator (mu PC) and a film bulk acoustic resonator (FBAR) gas sensor and offers advantages such as high sensitivity and rapid detection. By coating the mu PC with a nanoporous metal-organic framework material, effective sample pretreatment is achieved. The combination of mu PC and FBAR in one instrument maximizes their respective advantages, reducing the limit of detection of the analyte. The compact size and high portability of the prototype instrument make it suitable for in-field detection of CWAs.