Surface acoustic wave , vapor detection

Acoustic wave sensors are also used to detect nerve and blister agents. The surface acoustic wave chemical agent detector (SAW Mini-CAD) is a commercially available, pocket-sized instrument that can monitor for trace levels of toxic vapors of sulfur-based mustard agents (e.g., distilled mustard) and G nerve agents (e.g., tabun, sarin, soman) with a high degree of specificity. Colorimetric tubes are the... 

Amidoxime-Functionalized Coatings for Surface Acoustic Wave Detection of Simulant Vapors... 

Grate J W, Rose-Pehrsson S L, Venezky D L, Klusty M and Wohltjen H 1993 Smart sensor system for trace organophosphorus and organosulfur vapor detection employing a temperature-controlled array of surface acoustic wave sensors, automated sample preconcentration and pattern recognition Anal. Chem. 65 1868... 

Chemical sensors have been reported that are based on quartz micro balances or surface acoustic wave oscillators coated with the trimethylsilyl ethers of and 6 " and that are claimed to detect various solvent vapors in ppm amounts. ... 

Fig. 3.9 (Left) Surface acoustic wave (SAW) resonator and (right) SAW dual delay line device (on penny). Quartz-based SAW sensors, coated with chemically selective films, can detect chemical vapors. Sensor arrays, with diverse coatings, can detect multiple chemical vapors, image courtesy of pacific northwest national laboratory...

Vapor Detection with Surface Acoustic Wave Microsensors... 

This paper has dealt exclusively with SAW sensors that exploit the mass sensitivity of the device to achieve chemical vapor detection. Schemes to exploit the SAW sensitivity to coating conductance changes (17) or elastic modulus changes should afford new opportunities for imaginative chemical vapor sensor designs. Finally, the field of liquid phase chemical analysis may also yield to surface acoustic wave devices that utilize plate waves and horizontally polarized shear waves to minimize acoustic losses in the liquid (18). 

A coated surface-acoustic-wave (SAW) sensor capable of real-time, selective measurement of vinyl acetate vapor in the presence of several olefin and non-olefin cocontaminants is described. The coating film en loyed consists of the solid platinum-ethylene Ji-complex, trans-PtCl (ethylene)(pyridine). occluded in a polyisobutylene matrix. Exposure to vinyl acetate results in displacement of ethylene from the cott lex and formation of the vinyl acetate-substituted complex. Subsequent regeneration of the original reagent is possible by treatment with ethylene gas, in situ. A lower detection limit of 5 ppm of vinyl acetate is achieved for operation at 46 C. The industrial-hygiene applications of the sensor are discussed. 

Chemical sensors based on acoustic wave (AW) devices have been studied for a number of sensing applications, the majority of which fall in the category of gas and vapor detection (1-8). Recently, the use of these sensors in liquid environments has been explored (9-13). AW sensors utilize various types of acoustic waves, including the surface acoustic wave (SAW), the shear-horizontal acoustic plate mode (SH-APM) (10-13), and the Lamb wave (also a plate mode) (3.14). Even though most studies of these piezoelectric sensors have centered on SAW devices (1.2.4-8), differences in the propagation characteristics of the various acoustic modes make some better suited than others for a given sensing application. 

High Frequency Surface Acoustic Wave (SAW) Device for Toxic Vapor Detection Prospects and Challenges... 

This paper consists of a description of design considerations for development of small, hand-held vapor sampling analytical detection devices, some solutions to these design problems, and up-to-date results of testing activities on hand-held devices suitable for CW defense as well as CW destruction applications. Devices based on Ion Mobility Spectrometry and Surface Acoustic Waves are the two technologies discussed. 

It should be noted that a hybrid approach to design gas-sensing devices on plastic substrates can be used as well. In particular, a surface acoustic wave (SAW) chip, which require substrates with very different properties, can be transferred onto a plastic substrate Cobianu et al. (2007). Another interesting and new approach is the coating of passive (no power source on board) conventional RFID (radiofrequency identification) tags with chemically sensitive films to form a chemical sensor (Potyrailo and Morris 2007). The detection of several vapors of industrial, health, law enforcement, and security... 

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