A new silicon based microelectromechanical resonator for photoacoustic gas sensing

A new silicon based capacitive sensor is developed for photoacoustic gas detection. It is precisely designed to overcome damping losses and enhance signal-to-noise ratio. The measurement has been performed on calibrated concentrations of methane. For a 1s integration time in first harmonic detection, the resulted limit of detection (LOD) is of 667 ppmv reaching comparable performance to the bare on-beam Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS), a reference to compact and selective gas sensors.