Material studies of thin films of porous anodized Al2O3 have been undertaken to determine their applicability as sensing films for application on surface acoustic wave sensors. We describe the production of these films including their growth parameters and provide an analysis of their crystal morphology. These films were then exposed to various concentrations of analyte and their surface areas determined using Brunauer-Emmett-Teller-type analysis. Finally, the surface area as a function of anodization potential is provided for the films. © 2001 The Electrochemical Society. All rights reserved.

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We have developed instrumentation to enable the combination of surface acoustic wave (SAW) sensor measurements with direct, in-situ molecular spectroscopic measurements to understand the response of the SAW sensors with respect to the'interfacial chemistry of surface-confined sensing films interacting with gas-phase analytes. Specifically, the instrumentation and software was developed to perform in-situ Fourier-transform infrared external-reflectance spectroscopy (FTIR-ERS) on operating SAW devices during dosing of their chemically modified surfaces with analytes. By probing the surface with IR spectroscopy during gas exposure, it is possible to understand in unprecedented detail the interaction processes between the sorptive SAW coatings and the gaseous analyte molecules. In this report, we provide details of this measurement system, and also demonstrate the utility of these combined measurements by characterizing the SAW and FTIR-ERS responses of organic thin-film sensor coatings interacting with gas-phase analytes.

A microfabricated ultrafast GC×GC system, coupled with highly sensitive, low-power NEMS resonators, with handheld form factor for civilian, military, and space applications.