ANALYSIS OF THIN ROD FLEXURAL ACOUSTIC-WAVE GRAVIMETRIC SENSORS

An analysis of thin rod flexural acoustic wave gravimetric sensors is presented. The diameter of the thin rod is much less than a wavelength. The lowest order flexural acoustics mode, F11, is of interest. For small added masses, the calculated mass sensitivity is -1/(2ρa), where ρ is the density and a is the radius of the thin rod. Measurements of velocity dispersion of the F11 mode in 21-μm-diam gold wires are shown to agree well with the theoretical calculation. Devices based on thin rods are shown to potentially have the same advantages as plate-mode gravimetric sensors.