Enhanced sensitivity volatile detection with low power integrated micromechanical resonators

Very high aspect (length/thickness) ratio doubly clamped beams with integrated piezoelectric transducers are demonstrated for low power sensing of volatiles. The described approach allows for high yield fabrication of a dense array of suspended resonators that can be individually functionalized. Upon polymer coating, the resonators become highly sensitive to absorption of volatile compounds, allowing for detection at ppm-level concentrations of low-molecular weight analytes. The determined sensitivity enhancement is due to the significant contribution of vapor absorption-induced polymer swelling that results in axial stress formation in length restricted high aspect ratio beams.