In Situ Chemical Analysis via Acoustic-Emission Spectra

A method of in situ chemical analysis by use of small, simple, robust sensors has been proposed. The basis for the proposal is the discovery that chemical reactions emit acoustic waves, and that characteristic frequency spectra are associated with specific reactions. The acoustic frequencies of interest range from about 0.1 to several megahertz. If a newly recorded acoustic spectrum were to match a previously recorded spectrum of a known chemical reaction, then the newly recorded spectrum would be deemed to indicate the presence of that reaction. The amplitude of a spectrum would be taken as an indication of the rate of the corresponding reaction.