Volatile detection system using piezoelectric micromechanical resonators interfaced by an oscillator readout

In this paper, we demonstrate the implementation of a real-time volatile detection system using an electronic readout interfacing a functionalized piezoelectric micromechanical resonator for frequency shift tracking. The readout circuit is based on a trans-impedance sustaining amplifier and it is assembled from off-the-shelf components. The 2.08 MHz oscillator system achieves a measured Allan deviation of 3 Hz at 10 ms integration time. Exposure to varying concentrations of ethanol in a controlled dry nitrogen flow yielded a normalized sensitivity of -7.48 x 10(-6) ppm(-1). These results pave the way toward compact and portable measurement systems capable of ppm-level detection resolution for low-molecular weight volatile compounds. (C) 2012 Elsevier B.V. All rights reserved.